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                                                                Exhibit 10.1


                             MASTER LEASE AGREEMENT
                                     (QUASI)
                      dated as of MAY 1, 2001 ("AGREEMENT")

     THIS AGREEMENT is between GENERAL ELECTRIC CAPITAL CORPORATION (together
with its successors and assigns, if any, "LESSOR") and DYAX CORP. ("LESSEE").
Lessor has an office at 401 Merritt 7 2nd Floor, Norwalk, CT 06856. Lessee is a
corporation organized and existing under the laws of the state of Delaware.
Lessee's mailing address and chief place of business is One Kendall Square,
Building 600, Cambridge, MA 02139. This Agreement contains the general terms
that apply to the leasing of Equipment from Lessor to Lessee. Additional terms
that apply to the Equipment (term, rent, options, etc.) shall be contained on a
schedule ("SCHEDULE").

1.   LEASING:

     (a) Lessor agrees to lease to Lessee, and Lessee agrees to lease from
Lessor, the equipment and other property ("EQUIPMENT") described in any Schedule
signed by both parties.

     (b) Lessor shall purchase Equipment from the manufacturer or supplier
("SUPPLIER") and lease it to Lessee if on or before the Last Delivery Date
(specified in the Schedule) Lessor receives (i) a Schedule for the Equipment,
(ii) evidence of insurance which complies with the requirements of Section 8,
and (iii) such other documents as Lessor may reasonably request. Each of the
documents required above must be in form and substance satisfactory to Lessor.
Lessor hereby appoints Lessee its agent for inspection and acceptance of the
Equipment from the Supplier. Once the Schedule is signed, the Lessee may not
cancel the Schedule.

2.   TERM, RENT AND PAYMENT:

     (a) The rent payable for the Equipment and Lessee's right to use the
Equipment shall begin on the earlier of (i) the date when the Lessee signs the
Schedule and accepts the Equipment or (ii) when Lessee has accepted the
Equipment under a Certificate of Acceptance ("LEASE COMMENCEMENT DATE"). The
term of this Agreement shall be the period specified in the applicable Schedule.
The word "term" shall include all basic and any renewal terms.

     (b) Lessee shall pay rent to Lessor at its address stated above, except as
otherwise directed by Lessor. Rent payments shall be in the amount set forth in,
and due as stated in the applicable Schedule. If any Advance Rent (as stated in
the Schedule) is payable, it shall be due when the Lessee signs the Schedule.
Advance Rent shall be applied to the first rent payment and the balance, if any,
to the final rent payment(s) under such Schedule. In no event shall any Advance
Rent or any other rent payments be refunded to Lessee. If rent is not paid
within ten (10) days of its due date, Lessee agrees to pay a late charge of five
cents ($.05) per dollar on, and in addition to, the amount of such rent but not
exceeding the lawful maximum, if any.

     (c) Lessor shall not disturb Lessee's quiet enjoyment of the Equipment
during the term of the Agreement unless a default has occurred and is continuing
under this Agreement.

3.   TAXES:

     (a) If permitted by law, Lessee shall report and pay promptly all taxes,
fees and assessments due, imposed, assessed or levied against any Equipment (or
purchase, ownership, delivery, leasing, possession, use or operation thereof),
this Agreement (or any rents or receipts hereunder), any Schedule, Lessor or
Lessee by any governmental entity or taxing authority during or related to the
term of this Agreement, including, without limitation, all license and
registration fees, and all sales, use, personal property, excise, gross
receipts, franchise, stamp or other taxes, imposts, duties and charges, together
with any penalties, fines or interest thereon (collectively "TAXES"). Lessee
shall have no liability for Taxes imposed by the United States of America or any
State or political subdivision thereof which are on or measured by the net
income of Lessor. Lessee shall promptly reimburse Lessor (on an after tax basis)
for any Taxes charged to or assessed against Lessor. Lessee shall send Lessor a
copy of each report or return and evidence of Lessees payment of Taxes upon
request.

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     (b) Lessee's obligations, and Lessor's rights and privileges, contained in
this Section 3 shall survive the expiration or other termination of this
Agreement.

4.   REPORTS:

     (a) If any tax or other lien shall attach to any Equipment, Lessee will
notify Lessor in writing, within ten (10) days after Lessee becomes aware of the
tax or lien. The notice shall include the full particulars of the tax or lien
and the location of such Equipment on the date of the notice.

     (b) Lessee will deliver to Lessor Lessees complete financial statements,
certified by a recognized firm of certified public accountants, within ninety
(90) days of the close of each fiscal year of Lessee. If Lessor requests, Lessee
will deliver to Lessor copies of Lessee's quarterly financial report certified
by the chief financial officer of Lessee, within ninety (90) days of the close
of each fiscal quarter of Lessee. Lessee will deliver to Lessor all Forms 10-K
and 10Q, if any, filed with the Securities and Exchange Commission within thirty
(30) days after the date on which they are filed.

     (c) Lessor may inspect any Equipment during normal business hours after
giving Lessee reasonable prior notice.

     (d) Lessee will keep the Equipment at the Equipment Location (specified in
the applicable Schedule) and will give Lessor prior written notice of any
relocation of Equipment. If Lessor requests, Lessee will promptly notify Lessor
in writing of the location of any Equipment.

     (e) If any Equipment is lost or damaged (where the estimated repair costs
would exceed the greater of ten percent (10%) of the original Equipment cost or
ten thousand and 00/100 dollars ($10,000)), or is otherwise involved in an
accident causing personal injury or property damage, Lessee will promptly and
fully report the event to Lessor in writing.

     (f) Lessee will furnish a certificate of an authorized officer of Lessee
stating that he has reviewed the activities of Lessee and that, to the best of
his knowledge, there exists no default or event which with notice or lapse of
time (or both) would become such a default within thirty (30) days after any
request by Lessor.

     (g) Lessee will promptly notify Lessor of any change in Lessee's state of
incorporation or organization.

5.   DELIVERY, USE AND OPERATION:

     (a) All Equipment shall be shipped directly from the Supplier to Lessee.

     (b) Lessee agrees that the Equipment will be used by Lessee solely in the
conduct of its business and in a manner complying with all applicable laws,
regulations and insurance policies, and Lessee shall not discontinue use of the
Equipment.

     (c) Lessee will not move any equipment from the location specified on the
Schedule, without the prior written consent of Lessor.

     (d) Lessee will keep the Equipment free and clear of all liens and
encumbrances other than those which result from acts of Lessor.

     (e) Lessor shall not disturb Lessees quiet enjoyment of the Equipment
during the term of the Agreement unless a default has occurred and is continuing
under this Agreement.

6.   MAINTENANCE:

     (a) Lessee will, at its sole expense, maintain each unit of Equipment in
good operating order and repair, normal wear and tear excepted. The Lessee shall
also maintain the Equipment in accordance with manufacturers recommendations.
Lessee shall make all alterations or modifications required to comply with any
applicable law, rule or regulation during the term of this Agreement. If Lessor
requests, Lessee shall affix plates, tags or other identifying labels showing
ownership thereof by Lessee and Lessor's security interest therein. The tags or
labels shall be placed in a prominent position on each unit of Equipment.

     (b) Lessee will not attach or install anything on the Equipment that will
impair the originally intended function or use of such Equipment without the
prior written consent of Lessor. All additions, parts, supplies, accessories,
and equipment ("ADDITIONS") furnished or attached to any

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Equipment that are not readily removable shall become subject to the lien of
Lessor. All Additions shall be made only in compliance with applicable law.
Lessee will not attach or install any Equipment to or in any other personal or
real property without the prior written consent of Lessor.

7.   STIPULATED LOSS VALUE: If for any reason any unit of Equipment becomes worn
out, lost, stolen, destroyed, irreparably damaged or unusable ("CASUALTY
OCCURRENCES") Lessee shall promptly and fully notify Lessor in writing. Lessee
shall pay Lessor the sum of (i) the Stipulated Loss Value (see Schedule) of the
affected unit determined as of the rent payment date prior to the Casualty
Occurrence; and (ii) all rent and other amounts which are then due under this
Agreement on the Payment Date (defined below) for the affected unit. The Payment
Date shall be the next rent payment date after the Casualty Occurrence. Upon
payment of all sums due hereunder, the term of this lease as to such unit shall
terminate.

8.   INSURANCE:

     (a) Lessee shall bear the entire risk of any loss, theft, damage to, or
destruction of, any unit of Equipment from any cause whatsoever from the time
the Equipment is shipped to Lessee.

     (b) Lessee agrees, at its own expense, to keep all Equipment insured for
such amounts and against such hazards as Lessor may reasonably require. All such
policies shall be with companies, and on terms, reasonably satisfactory to
Lessor. The insurance shall include coverage for damage to or loss of the
Equipment, liability for personal injuries, death or property damage. Lessor
shall be named as additional insured with a loss payable clause in favor of
Lessor, as its interest may appear, irrespective of any breach of warranty or
other act or omission of Lessee. The insurance shall provide for liability
coverage in an amount equal to at least ONE MILLION U.S. DOLLARS ($1,000,000.00)
total liability per occurrence, unless otherwise stated in any Schedule. The
casualty/property damage coverage shall be in an amount equal to the higher of
the Stipulated Loss value or the full replacement cost of the Equipment. No
insurance shall be subject to any co-insurance clause. The insurance policies
shall provide that the insurance may not be altered or canceled by the insurer
until after thirty (30) days written notice to Lessor. Lessee agrees to deliver
to Lessor evidence of insurance reasonably satisfactory to Lessor.

     (c) Lessee hereby appoints Lessor as Lessee's attorney-in-fact to make
proof of loss and claim for insurance, and to make adjustments with insurers and
to receive payment of and execute or endorse all documents, checks or drafts in
connection with insurance payments. Lessor shall not act as Lessees
attorney-in-fact unless Lessee is in default. Lessee shall pay any reasonable
expenses of Lessor in adjusting or collecting insurance. Lessee will not make
adjustments with insurers except with respect to claims for damage to any unit
of Equipment where the repair costs are less than the lesser of ten percent
(10%) of the original Equipment cost or ten thousand and 00/100 dollars
($10,000). Lessor may, at its option, apply proceeds of insurance, in whole or
in part, to (i) repair or replace Equipment or any portion thereof, or (ii)
satisfy any obligation of Lessee to Lessor under this Agreement.

9.   RETURN OF EQUIPMENT:

     (a) At the expiration or termination of this Agreement or any Schedule,
Lessee shall perform any testing and repairs required to place the units of
Equipment in the same condition and appearance as when received by Lessee
(reasonable wear and tear excepted) and in good working order for the original
intended purpose of the Equipment. If required the units of Equipment shall be
deinstalled, disassembled and crated by an authorized manufacturer's
representative or such other service person as is reasonably satisfactory to
Lessor. Lessee shall remove installed markings that are not necessary for the
operation, maintenance or repair of the Equipment. All Equipment will be
cleaned, cosmetically acceptable, and in such condition as to be immediately
installed into use in a similar environment for which the Equipment was
originally intended to be used. All waste material and fluid must be removed
from the Equipment and disposed of in accordance with then current waste
disposal laws. Lessee shall return the units of Equipment to a location within
the continental United States as Lessor shall direct. Lessee shall obtain and
pay for a policy of transit insurance for the redelivery period in an amount
equal to the replacement value of the Equipment. The transit insurance must name
Lessor as the loss payee. The Lessee shall pay for all costs to comply with this
section (a).

     (b) Until Lessee has fully complied with the requirements of Section 9(a)
above, Lessee's rent payment obligation and all other obligations under this
Agreement shall continue from month to month notwithstanding any expiration or
termination of the lease term. Lessor may terminate the Lessee's right to use
the Equipment upon ten (10) days notice to Lessee.

     (c) Lessee shall provide to Lessor a detailed inventory of all components
of the Equipment including model and serial numbers. Lessee shall also provide
an up-to-date copy of all other documentation pertaining to the Equipment. All
service manuals, blue prints, process flow diagrams,

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operating manuals, inventory and maintenance records shall be given to Lessor at
least ninety (90) days and not more than one hundred twenty (120) days prior to
lease termination.

     (d) Lessee shall make the Equipment available for on-site operational
inspections by potential purchasers at least one hundred twenty (120) days prior
to and continuing up to lease termination. Lessor shall provide Lessee with
reasonable notice prior to any inspection. Lessee shall provide personnel, power
and other requirements necessary to demonstrate electrical, hydraulic and
mechanical systems for each item of Equipment.

10.  DEFAULT AND REMEDIES:

     (a) Lessor may in writing declare this Agreement in default if: (i) Lessee
breaches its obligation to pay rent or any other sum when due and fails to cure
the breach within ten (10) days; (ii) Lessee breaches any of its insurance
obligations under Section 8; (iii) Lessee breaches any of its other obligations
and fails to cure that breach within thirty (30) days after written notice from
Lessor; (iv) any representation or warranty made by Lessee in connection with
this Agreement shall be false or misleading in any material respect; (v) Lessee
or any guarantor or other obligor for the Lessee's obligations hereunder
("GUARANTOR") becomes insolvent or ceases to do business as a going concern;
(vi) any Equipment is illegally used; (vii) if Lessee or any Guarantor is a
natural person, any death or incompetency of Lessee or such Guarantor; or (viii)
a petition is filed by or against Lessee or any Guarantor under any bankruptcy
or insolvency laws and in the event of an involuntary petition, the petition is
not dismissed within forty-five (45) days of the filing date. The default
declaration shall apply to all Schedules unless specifically excepted by Lessor.

     (b) After a default, at the request of Lessor, Lessee shall comply with the
provisions of Section 9(a). Lessee hereby authorizes Lessor to peacefully enter
any premises where any Equipment may be and take possession of the Equipment.
Lessee shall immediately pay to Lessor without further demand as liquidated
damages for loss of a bargain and not as a penalty, the Stipulated Loss Value of
the Equipment (calculated as of the rent payment date prior to the declaration
of default), and all rents and other sums then due under this Agreement and all
Schedules. Lessor may terminate this Agreement as to any or all of the
Equipment. A termination shall occur only upon written notice by Lessor to
Lessee and only as to the units of Equipment specified in any such notice.
Lessor may, but shall not be required to, sell Equipment at private or public
sale, in bulk or in parcels, with or without notice, and without having the
Equipment present at the place of sale. Lessor may also, but shall not be
required to, lease, otherwise dispose of or keep idle all or part of the
Equipment. Lessor may use Lessee's premises for a reasonable period of time for
any or all of the purposes stated above without liability for rent, costs,
damages or otherwise. The proceeds of sale, lease or other disposition, if any,
shall be applied in the following order of priorities: (i) to pay all of
Lessor's costs, charges and expenses incurred in taking, removing, holding,
repairing and selling, leasing or otherwise disposing of Equipment; then, (ii)
to the extent not previously paid by Lessee, to pay Lessor all sums due from
Lessee under this Agreement; then (iii) to reimburse to Lessee any sums
previously paid by Lessee as liquidated damages; and then (iv) to Lessee, if
there exists any surplus. Lessee shall immediately pay any deficiency in (i) and
(ii) above.

     (c) The foregoing remedies are cumulative, and any or all thereof may be
exercised instead of or in addition to each other or any remedies at law, in
equity, or under statute. Lessee waives notice of sale or other disposition (and
the time and place thereof), and the manner and place of any advertising. Lessee
shall pay Lessor's actual attorney's fees incurred in connection with the
enforcement, assertion, defense or preservation of Lessor's rights and remedies
under this Agreement, or if prohibited by law, such lesser sum as may be
permitted. Waiver of any default shall not be a waiver of any other or
subsequent default.

     (d) Any default under the terms of this or any other agreement between
Lessor and Lessee may be declared by Lessor a default under this and any such
other agreement.

11.  ASSIGNMENT: LESSEE SHALL NOT SELL, TRANSFER, ASSIGN, ENCUMBER OR SUBLET ANY
EQUIPMENT OR THE INTEREST OF LESSEE IN THE EQUIPMENT WITHOUT THE PRIOR WRITTEN
CONSENT OF LESSOR. Lessor may, without the consent of Lessee, assign this
Agreement, any Schedule or the right to enter into a Schedule. Lessee agrees
that if Lessee receives written notice of an assignment from Lessor, Lessee will
pay all rent and all other amounts payable under any assigned Schedule to such
assignee or as instructed by Lessor. Lessee also agrees to confirm in writing
receipt of the notice of assignment as may be reasonably requested by assignee.
Lessee hereby waives and agrees not to assert against any such assignee any
defense, set-off, recoupment claim or counterclaim which Lessee has or may at
any time have against Lessor for any reason whatsoever.

12.  NET LEASE: Lessee is unconditionally obligated to pay all rent and other
amounts due for the entire lease term no matter what happens, even if the
Equipment is damaged or destroyed, if it is defective or if Lessee no longer can
use it. Lessee is not entitled to reduce or set-off against rent or other
amounts due to Lessor or to anyone to whom Lessor assigns this Agreement or any
Schedule whether Lessees claim arises

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out of this Agreement, any Schedule, any statement by Lessor, Lessors liability
or any manufacturers liability, strict liability, negligence or otherwise.

13.  INDEMNIFICATION:

     (a) Lessee hereby agrees to indemnify Lessor, its agents, employees,
successors and assigns (on an after tax basis) from and against any and all
losses, damages, penalties, injuries, claims, actions and suits, including legal
expenses, of whatsoever kind and nature arising out of or relating to the
Equipment or this Agreement, except to the extent the losses, damages,
penalties, injuries, claims, actions, suits or expenses result from Lessors
gross negligence or willful misconduct ("CLAIMS"). This indemnity shall include,
but is not limited to, Lessor's strict liability in tort and Claims, arising out
of (i) the selection, manufacture, purchase, acceptance or rejection of
Equipment, the ownership of Equipment during the term of this Agreement, and the
delivery, lease, possession, maintenance, uses, condition, return or operation
of Equipment (including, without limitation, latent and other defects, whether
or not discoverable by Lessor or Lessee and any claim for patent, trademark or
copyright infringement or environmental damage) or (ii) the condition of
Equipment sold or disposed of after use by Lessee, any sublessee or employees of
Lessee. Lessee shall, upon request, defend any actions based on, or arising out
of, any of the foregoing.

     (b) All of Lessor's rights, privileges and indemnities contained in this
Section 13 shall survive the expiration or other termination of this Agreement.
The rights, privileges and indemnities contained herein are expressly made for
the benefit of, and shall be enforceable by Lessor, its successors and assigns.

14.  DISCLAIMER: LESSEE ACKNOWLEDGES THAT IT HAS SELECTED THE EQUIPMENT WITHOUT
ANY ASSISTANCE FROM LESSOR, ITS AGENTS OR EMPLOYEES. LESSOR DOES NOT MAKE, HAS
NOT MADE, NOR SHALL BE DEEMED TO MAKE OR HAVE MADE, ANY WARRANTY OR
REPRESENTATION, EITHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, WITH RESPECT TO THE
EQUIPMENT LEASED UNDER THIS AGREEMENT OR ANY COMPONENT THEREOF, INCLUDING,
WITHOUT LIMITATION, ANY WARRANTY AS TO DESIGN, COMPLIANCE WITH SPECIFICATIONS,
QUALITY OF MATERIALS OR WORKMANSHIP, MERCHANTABILITY, FITNESS FOR ANY PURPOSE,
USE OR OPERATION, SAFETY, PATENT, TRADEMARK OR COPYRIGHT INFRINGEMENT, OR TITLE.
All such risks, as between Lessor and Lessee, are to be borne by Lessee. Without
limiting the foregoing, Lessor shall have no responsibility or liability to
Lessee or any other person with respect to any of the following: (i) any
liability, loss or damage caused or alleged to be caused directly or indirectly
by any Equipment, any inadequacy thereof, any deficiency or defect (latent or
otherwise) of the Equipment, or any other circumstance in connection with the
Equipment; (ii) the use, operation or performance of any Equipment or any risks
relating to it; (iii) any interruption of service, loss of business or
anticipated profits or consequential damages; or (iv) the delivery, operation,
servicing, maintenance, repair, improvement or replacement of any Equipment. If,
and so long as, no default exists under this Agreement, Lessee shall be, and
hereby is, authorized during the term of this Agreement to assert and enforce,
whatever claims and rights Lessor may have against any Supplier of the Equipment
at Lessee's sole cost and expense, in the name of and for the account of Lessor
and/or Lessee, as their interests may appear.

15.  REPRESENTATIONS AND WARRANTIES OF LESSEE:  Lessee makes each of the
following representations and warranties to Lessor on the date hereof and on
the date of execution of each Schedule:

     (a) Lessee has adequate power and capacity to enter into, and perform
under, this Agreement and all related documents (together, the "DOCUMENTS").
Lessee is duly qualified to do business wherever necessary to carry on its
present business and operations, including the jurisdiction(s) where the
Equipment is or is to be located.

     (b) The Documents have been duly authorized, executed and delivered by
Lessee and constitute valid, legal and binding agreements, enforceable in
accordance with their terms, except to the extent that the enforcement of
remedies may be limited under applicable bankruptcy and insolvency laws.

     (c) No approval, consent or withholding of objections is required from any
governmental authority or entity with respect to the entry into or performance
by Lessee of the Documents except such as have already been obtained.

     (d) The entry into and performance by Lessee of the Documents will not: (i)
violate any judgment, order, law or regulation applicable to Lessee or any
provision of Lessee's Certificate of Incorporation or bylaws; or (ii) result in
any breach of, constitute a default under or result in the creation of any lien,
charge, security interest or other encumbrance upon any Equipment pursuant to
any indenture, mortgage, deed of trust, bank loan or credit agreement or other
instrument (other than this Agreement) to which Lessee is a party.

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     (e) There are no suits or proceedings pending or threatened in court or
before any commission, board or other administrative agency against or affecting
Lessee, which if decided against Lessee will have a material adverse effect on
the ability of Lessee to fulfill its obligations under this Agreement.

     (f) The Equipment accepted under any Certificate of Acceptance is and will
remain tangible personal property.

     (g) Each financial statement delivered to Lessor has been prepared in
accordance with generally accepted accounting principles consistently applied.
Since the date of the most recent financial statement, there has been no
material adverse change.

     (h) Lessee's exact legal name is as set forth in the first sentence of this
Agreement and Lessee is and will be at all times validly existing and in good
standing under the laws of the State of its incorporation (specified in the
first sentence of this Agreement).

     (i) The Equipment will at all times be used for commercial or business
purposes.

16.  OWNERSHIP FOR TAX PURPOSES, GRANT OF SECURITY INTEREST; USURY SAVINGS:

     (a) For income tax purposes, the parties hereto agree that it is their
mutual intention that Lessee shall be considered the owner of the Equipment.
Accordingly, Lessor agrees (i) to treat Lessee as the owner of the Equipment on
its federal income tax return, (ii) not to take actions or positions
inconsistent with such treatment on or with respect to its federal income tax
return, and (iii) not to claim any tax benefits available to an owner of the
Equipment on or with respect to its federal income tax return. The foregoing
undertakings by Lessor shall not be violated by Lessor's taking a tax position
inconsistent with the foregoing sentence to the extent such a position is
required by law or is taken through inadvertence so long as such inadvertent tax
position is reversed by Lessor promptly upon its discovery. Lessor shall in no
event be liable to Lessee if Lessee fails to secure any of the tax benefits
available to the owner of the Equipment.

     (b) Lessee hereby grants to Lessor a first security interest in the
Equipment, together with all additions, attachments, accessions, accessories and
accessions thereto whether or not furnished by the Supplier of the Equipment and
any and all substitutions, replacements or exchanges therefor, and any and all
insurance and/or other proceeds of the property in and against which a security
interest is granted hereunder. Notwithstanding anything to the contrary
contained elsewhere in this Agreement, to the extent that Lessor asserts a
purchase money security interest in any items of Equipment ("PMSI EQUIPMENT"):
(i) the PMSI Equipment shall secure only those sums which have been advanced by
Lessor for the purchase of the PMSI Equipment, or the acquisition of rights
therein, or the use thereof (the "PMSI INDEBTEDNESS"), and (ii) no other
Equipment shall secure the PMSI Indebtedness.

     (c) It is the intention of the parties hereto to comply with any applicable
usury laws to the extent that any Schedule is determined to be subject to such
laws; accordingly, it is agreed that, notwithstanding any provision to the
contrary in any Schedule or this Agreement, in no event shall any Schedule
require the payment or permit the collection of interest in excess of the
maximum amount permitted by applicable law. If any such excess interest is
contracted for, charged or received under any Schedule or this Agreement, or in
the event that all of the principal balance shall be prepaid, so that under any
of such circumstances the amount of interest contracted for, charged or received
under any Schedule or this Agreement shall exceed the maximum amount of interest
permitted by applicable law, then in such event (i) the provisions of this
paragraph shall govern and control, (ii) neither Lessee nor any other person or
entity now or hereafter liable for the payment hereof shall be obligated to pay
the amount of such interest to the extent that it is in excess of the maximum
amount of interest permitted by applicable law, (iii) any such excess which may
have been collected shall be either applied as a credit against the then unpaid
principal balance or refunded to Lessee, at the option of the Lessor, and (iv)
the effective rate of interest shall be automatically reduced to the maximum
lawful contract rate allowed under applicable law as now or hereafter construed
by the courts having jurisdiction thereof. It is further agreed that without
limitation of the foregoing, all calculations of the rate of interest contracted
for, charged or received under any Schedule or this Agreement which are made for
the purpose of determining whether such rate exceeds the maximum lawful contract
rate, shall be made, to the extent permitted by applicable law, by amortizing,
prorating, allocating and spreading in equal parts during the period of the full
stated term of the indebtedness evidenced hereby, all interest at any time
contracted for, charged or received from Lessee or otherwise by Lessor in
connection with such indebtedness; provided, however, that if any applicable
state law is amended or the law of the United States of America preempts any
applicable state law, so that it becomes lawful for Lessor to receive a greater
interest per annum rate than is presently allowed, the Lessee agrees that, on
the effective date of such amendment or preemption, as the case may be, the
lawful maximum hereunder shall be increased to the maximum interest per annum
rate allowed by the amended state law or the law of the United States of
America.

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17.  EARLY TERMINATION:

     (a) On or after the First Termination Date (specified in the applicable
Schedule), Lessee may, so long as no default exists hereunder, terminate this
Agreement as to all (but not less than all) of the Equipment on such Schedule as
of a rent payment date ("TERMINATION DATE"). Lessee must give Lessor at least
ninety (90) days prior written notice of the termination.

     (b) Lessee shall, and Lessor may, solicit cash bids for the Equipment on an
AS IS, WHERE IS BASIS without recourse to or warranty from Lessor, express or
implied ("AS IS BASIS"). Prior to the Termination Date, Lessee shall (i) certify
to Lessor any bids received by Lessee and (ii) pay to Lessor (A) the Termination
Value (calculated as of the rent due on the Termination Date) for the Equipment,
and (B) all rent and other sums due and unpaid as of the Termination Date.

     (c) If all amounts due hereunder have been paid on the Termination Date,
Lessor shall (i) sell the Equipment on an AS IS BASIS for cash to the highest
bidder and (ii) refund the proceeds of such sale (net of any related expenses)
to Lessee up to the amount of the Termination Value. If such sale is not
consummated, no termination shall occur and Lessor shall refund the Termination
Value (less any expenses incurred by Lessor) to Lessee.

     (d) Notwithstanding the foregoing, Lessor may elect by written notice, at
any time prior to the Termination Date, not to sell the Equipment. In that
event, on the Termination Date Lessee shall (i) return the Equipment (in
accordance with Section 9) and (ii) pay to Lessor all amounts required under
Section 17(b) less the amount of the highest bid certified by Lessee to Lessor.

18.  EARLY PURCHASE OPTION:

     (a) Lessee may purchase on an AS IS BASIS all (but not less than all) of
the Equipment on any Schedule on any Rent Payment Date after the First
Termination Date specified in the applicable Schedule but prior to the last Rent
Payment Date of such Schedule (the "EARLY PURCHASE DATE"), for a price equal to
(i) the Termination Value (calculated as of the Early Purchase Date) for the
Equipment, and (ii) all rent and other sums due and unpaid as of the Early
Purchase Date (the "EARLY OPTION PRICE"), plus all applicable sales taxes.
Lessee must notify Lessor of its intent to purchase the Equipment in writing at
least thirty (30) days, but not more than two hundred seventy (270) days, prior
to the Early Purchase Date. If Lessee is in default or if the Schedule or this
Agreement has already been terminated, Lessee may not purchase the Equipment.
(The purchase option granted by this subsection shall be referred to herein as
the "EARLY PURCHASE OPTION").

     (b) If Lessee exercises its Early Purchase Option, then on the Early
Purchase Date, Lessee shall pay to Lessor any rent and other sums due and unpaid
on the Early Purchase Date and Lessee shall pay the Early Option Price, plus all
applicable sales taxes, to Lessor in cash.

19.  END OF LEASE PURCHASE OPTION: Lessee may, at lease expiration, purchase all
(but not less than all) of the Equipment on any Schedule on an AS IS BASIS for
cash equal to the amount indicated on such Schedule (the "OPTION PAYMENT"), plus
all applicable sales taxes. The Option Payment, plus all applicable sales taxes,
shall be due and payable in immediately available funds on the expiration date
of such Schedule. Lessee must notify Lessor of its intent to purchase the
Equipment in writing at least one hundred eighty (180) days prior to the
expiration date of the Schedule. If Lessee is in default, or if the Schedule or
this Agreement has already been terminated, Lessee may not purchase the
Equipment.

20.  MISCELLANEOUS:

     (a) LESSEE AND LESSOR UNCONDITIONALLY WAIVE THEIR RIGHTS TO A JURY TRIAL OF
ANY CLAIM OR CAUSE OF ACTION BASED UPON OR ARISING OUT OF THIS AGREEMENT, ANY OF
THE RELATED DOCUMENTS, ANY DEALINGS BETWEEN LESSEE AND LESSOR RELATING TO THE
SUBJECT MATTER OF THIS TRANSACTION OR ANY RELATED TRANSACTIONS, AND/OR THE
RELATIONSHIP THAT IS BEING ESTABLISHED BETWEEN LESSEE AND LESSOR. THE SCOPE OF
THIS WAIVER IS INTENDED TO BE ALL ENCOMPASSING OF ANY AND ALL DISPUTES THAT MAY
BE FILED IN ANY COURT. THIS WAIVER IS IRREVOCABLE. THIS WAIVER MAY NOT BE
MODIFIED EITHER ORALLY OR IN WRITING. THE WAIVER ALSO SHALL APPLY TO ANY
SUBSEQUENT AMENDMENTS, RENEWALS, SUPPLEMENTS OR MODIFICATIONS TO THIS AGREEMENT,
ANY RELATED DOCUMENTS, OR TO ANY OTHER DOCUMENTS OR AGREEMENTS RELATING TO THIS
TRANSACTION OR ANY RELATED TRANSACTION. THIS AGREEMENT MAY BE FILED AS A WRITTEN
CONSENT TO A TRIAL BY THE COURT.

<Page>

     (b) Any cancellation or termination by Lessor of this Agreement, any
Schedule, supplement or amendment hereto, or the lease of any Equipment
hereunder shall not release Lessee from any then outstanding obligations to
Lessor hereunder. All Equipment shall at all times remain personal property even
though it may be attached to real property. The Equipment shall not become part
of any other property by reason of any installation in, or attachment to, other
real or personal property.

     (c) Time is of the essence of this Agreement. Lessor's failure at any time
to require strict performance by Lessee of any of the provisions hereof shall
not waive or diminish Lessor's right at any other time to demand strict
compliance with this Agreement. Lessee agrees, upon Lessor's request, to
execute, or otherwise authenticate, any document, record or instrument necessary
or expedient for filing, recording or perfecting the interest of Lessor or to
carry out the intent of this Agreement. In addition, Lessee hereby authorizes
Lessor to file a financing statement and amendments thereto describing the
Equipment described in any and all Schedules now and hereafter executed pursuant
hereto and adding any other collateral described therein and containing any
other information required by the applicable Uniform Commercial Code. Lessee
irrevocably grants to Lessor the power to sign Lessee's name and generally to
act on behalf of Lessee to execute and file financing statements and other
documents pertaining to any or all of the Equipment. All notices required to be
given hereunder shall be deemed adequately given if sent by registered or
certified mail to the addressee at its address stated herein, or at such other
place as such addressee may have specified in writing. This Agreement and any
Schedule and Annexes thereto constitute the entire agreement of the parties with
respect to the subject matter hereof. NO VARIATION OR MODIFICATION OF THIS
AGREEMENT OR ANY WAIVER OF ANY OF ITS PROVISIONS OR CONDITIONS, SHALL BE VALID
UNLESS IN WRITING AND SIGNED BY AN AUTHORIZED REPRESENTATIVE OF THE PARTIES
HERETO.

     (d) If Lessee does not comply with any provision of this Agreement, Lessor
shall have the right, but shall not be obligated, to effect such compliance, in
whole or in part. All reasonable amounts spent and obligations incurred or
assumed by Lessor in effecting such compliance shall constitute additional rent
due to Lessor. Lessee shall pay the additional rent within five days after the
date Lessor sends notice to Lessee requesting payment. Lessor's effecting such
compliance shall not be a waiver of Lessee's default.

     (e) Any rent or other amount not paid to Lessor when due shall bear
interest, from the due date until paid, at the lesser of eighteen percent (18%)
per annum or the maximum rate allowed by law. Any provisions in this Agreement
and any Schedule that are in conflict with any statute, law or applicable rule
shall be deemed omitted, modified or altered to conform thereto.

     (f) Lessee hereby irrevocably authorizes Lessor to adjust the Capitalized
Lessor's Cost up or down by no more than ten percent [10%] within each Schedule
to account for equipment change orders, equipment returns, invoicing errors, and
similar matters. Lessee acknowledges and agrees that the rent shall be adjusted
as a result of the change in the Capitalized Lessor's Cost. Lessor shall send
Lessee a written notice stating the final Capitalized Lessor's Cost, if it has
changed.

     (g) THIS AGREEMENT AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES HEREUNDER
SHALL IN ALL RESPECTS BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH, THE
INTERNAL LAWS OF THE STATE OF CONNECTICUT (WITHOUT REGARD TO THE CONFLICT OF
LAWS PRINCIPLES OF SUCH STATE), INCLUDING ALL MATTERS OF CONSTRUCTION, VALIDITY
AND PERFORMANCE, REGARDLESS OF THE LOCATION OF THE EQUIPMENT.

     (h) Any cancellation or termination by Lessor, pursuant to the provisions
of this Agreement, any Schedule, supplement or amendment hereto, of the lease of
any Equipment hereunder, shall not release Lessee from any then outstanding
obligations to Lessor hereunder.

     (i) To the extent that any Schedule would constitute chattel paper, as such
term is defined in the Uniform Commercial Code as in effect in any applicable
jurisdiction, no security interest therein may be created through the transfer
or possession of this Agreement in and of itself without the transfer or
possession of the original of a Schedule executed pursuant to this Agreement and
incorporating this Agreement by reference; and no security interest in this
Agreement and a Schedule may be created by the transfer or possession of any
counterpart of the Schedule other than the original thereof, which shall be
identified as the document marked Original and all other counterparts shall be
marked Duplicate.

<Page>

     IN WITNESS WHEREOF, Lessee and Lessor have caused this Agreement to be
executed by their duly authorized representatives as of the date first above
written.

LESSOR:                                         LESSEE:


GENERAL ELECTRIC CAPITAL CORPORATION            DYAX CORP.


By:  /s/ John Edel                              By:  /s/ Stephen S. Galliker
     --------------------------------                ---------------------------

Name: John Edel                                 Name: Stephen S. Galliker
      -------------------------------                 --------------------------

Title: Senior Vice President                    Title: Executive Vice President
       ------------------------------                  -------------------------

<Page>

                                    AMENDMENT

     THIS AMENDMENT is made as of the 27th day of September, 2001, between
General Electric Capital Corporation ("Lessor") and Dyax Corp. ("Lessee") in
connection with that certain Master Lease Agreement, dated or dated as of May 1,
2001 ("Agreement"). The terms of this Amendment are hereby incorporated into the
Agreement as though fully set forth therein. Section references below refer to
the section numbers of the Agreement. The Agreement is hereby amended as
follows:

     PREAMBLE.

     This section is hereby amended and replaced with the following:

          "THIS AGREEMENT is between GENERAL ELECTRIC CAPITAL CORPORATION
          (together with its successors and assigns, if any, "LESSOR") and DYAX,
          CORP. ("LESSEE"). Lessor has an office at 401 Merritt 7 2nd Floor,
          Norwalk, CT 06856. Lessee is a corporation organized and existing
          under the laws of the state of Delaware. Lessee's mailing address and
          chief place of business is One Kendall Square, Building 600,
          Cambridge, Massachusetts 02139. This Agreement contains the general
          terms that apply to the leasing of Equipment from Lessor to Lessee and
          the financing of Leasehold Improvements by Lessor on behalf of Lessee.
          Additional terms that apply to the Equipment and Leasehold
          Improvements (term, rent, options, etc.) shall be contained on a
          schedule covering such Equipment or Leasehold Improvements, as
          applicable (each a "SCHEDULE")."

     1.   LEASING.

     Subsection (a) is hereby amended and replaced with the following:

          "Lessor agrees to lease to Lessee, and Lessee agrees to lease from
          Lessor, the Equipment and Lessor agrees to finance on behalf of the
          Lessee the Leasehold Improvements. As used in this Agreement,
          "Equipment" means any equipment described on any Schedule signed by
          both parties; provided, however, that in no event shall any Leasehold
          Improvements constitute Equipment. As used in this Agreement,
          "Leasehold Improvements" means any of the following items of property
          financed by the Lessor under a Schedule signed by both parties: any
          fixtures (which expressly includes for purposes of this instrument
          fume hoods and laboratory benches), equipment, improvements and
          appurtenances attached to or built into the premises leased by the
          Lessee, as tenant (whether by the landlord at such premises or by the
          Lessee), and any electric, plumbing, heating or sprinkling systems,
          fixtures, outlets, vaults, paneling, molding, shelving, radiator
          enclosures, cork, rubber, linoleum and composition floors,
          ventilating, silencing, air conditioning and cooling equipment located
          at any premises leased by the Lessee, as tenant, whether or not
          attached to or built into such premises."

     Subsection (b) is hereby amended and replaced with the following:

          "Lessor shall purchase Equipment from the manufacturer or supplier
          ("SUPPLIER") and lease it to Lessee if on or before the Last Delivery
          Date (specified in the Schedule) Lessor receives (i) a Schedule for
          the Equipment, (ii) evidence of insurance which complies with the
          requirements of Section 8, and (iii) such other documents as Lessor
          may reasonably request. Lessor shall finance Leasehold Improvements if
          on or before the Last Delivery Date (specified in the Schedule) Lessor
          receives (i) a Schedule for the Leasehold Improvements and (iii) such
          other documents as Lessor may reasonably request. Each of the
          documents required above must be in form and substance satisfactory to
          Lessor. Lessor hereby appoints Lessee its agent for inspection and
          acceptance of the Equipment from the Supplier. Once the Schedule is
          signed, the Lessee may not cancel the Schedule."

     2.   TERM, RENT AND PAYMENT.

     Subsection (a) is hereby amended and replaced with the following:

          "The rent payable for the Equipment or the Leasehold Improvements, as
          applicable, shall begin on the earlier of (i) the date when the Lessee
          signs the Schedule and accepts the Equipment or the Leasehold
          Improvements under such Schedule or (ii) when Lessee has accepted the
          Equipment under a Certificate of Acceptance ("LEASE COMMENCEMENT
          DATE"). The term of this Agreement shall be the period specified in
          the applicable Schedule. The word "term" shall include all basic and
          any renewal terms. The word "rent" as used in this Agreement and the
          Schedules shall mean the periodic rental payment for the Equipment or
          the periodic finance payment for the Leasehold Improvements, as the
          context may require."

     Subsection (c) is hereby amended and replaced with the following:

<Page>

          "Lessor shall not disturb Lessee's quiet enjoyment of the Equipment
          during the term of the Agreement unless a default has occurred and is
          continuing under this Agreement. In no event shall Lessor disturb
          Lessee's quiet enjoyment of the Leasehold Improvements."

     4.   REPORTS.

     Subsection (a) is hereby amended and replaced with the following:

          "If any tax or other lien shall attach to any Equipment, Lessee will
          notify Lessor in writing, within ten (10) days after Lessee becomes
          aware of the tax or other lien. The notice shall include the full
          particulars of the tax or other lien and the location of such
          Equipment on the date of the notice."

     Subsection (b) is hereby amended and replaced with the following:

          "Lessee will deliver to Lessor all Forms 10-K and 10Q, if any, filed
          with the Securities and Exchange Commission within thirty (30) days
          after the date on which they are filed."

     5.   DELIVERY, USE AND OPERATION.

     Subsection (b) is hereby amended and replaced with the following:

          "Lessee agrees that the Equipment will be used by Lessee solely in the
          conduct of its business and in a manner complying with all applicable
          laws, regulations and insurance policies."

     7.   STIPULATED LOSS VALUE.

     This section is hereby amended and replaced with the following:

          "If for any reason any unit of Equipment becomes lost, stolen,
          destroyed, irreparably damaged or permanently unusable ("CASUALTY
          OCCURRENCES") Lessee shall promptly and fully notify Lessor in
          writing. Lessee shall pay Lessor the sum of (i) the Stipulated Loss
          Value (see Schedule) of the affected unit determined as of the rent
          payment date next succeeding the Casualty Occurrence; and (ii) all
          rent and other amounts which are then due under this Agreement on the
          Payment Date (defined below) for the affected unit. The Payment Date
          shall be the rent payment date immediately prior to the Casualty
          Occurrence. Upon payment of all sums due hereunder, the term of this
          lease as to such unit shall terminate."

     8.   INSURANCE.

     Subsection (a) is hereby amended and replaced with the following:

          "As between the Lessor and the Lessee, Lessee shall bear the entire
          risk of any loss, theft, damage to, or destruction of, any unit of
          Equipment from any cause whatsoever from the time the Equipment is
          shipped to Lessee until it is delivered to the Lessor at the end of
          the Term of the applicable Schedule pursuant to Sections 9 and 10 of
          this Agreement."

     Subsection (c) is hereby amended and replaced with the following:

          "Lessee hereby appoints Lessor as Lessee's attorney-in-fact to make
          proof of loss and claim for insurance, and to make adjustments with
          insurers and to receive payment of and execute or endorse all
          documents, checks or drafts in connection with insurance payments.
          Lessor shall not act as Lessees attorney-in-fact unless Lessee is in
          default. In the event Lessee is not in default and damage is not the
          result of a Casualty Occurrence, then Lessee is permitted to make any
          claims adjustments. Lessee shall pay any reasonable expenses of Lessor
          in adjusting or collecting insurance. Unless otherwise stated herein,
          Lessee will not make adjustments with insurers except with respect to
          claims for damage to any unit of Equipment where the repair costs are
          less than the lesser of ten percent (10%) of the original Equipment
          cost or ten thousand and 00/100 dollars ($10,000). During the
          occurrence of a default or in respect of a Casualty Occurrence, Lessor
          may, at its sole option, apply proceeds of insurance, in whole or in
          part, to (i) repair or replace Equipment or any portion thereof, or
          (ii) satisfy any obligation of Lessee to Lessor under this Agreement.

     9.   RETURN OF EQUIPMENT.

<Page>

     Subsection (a) is hereby amended and replaced with the following:

          "At the expiration or termination of any Schedule covering Equipment,
          Lessee will be obligated to take the actions specified in this Section
          9 with respect to the Equipment covered by such Schedule, unless the
          Lessee purchases the Equipment in accordance with the terms of this
          Agreement and such Schedule. Lessee shall perform any testing and
          repairs required to place the units of Equipment in the same condition
          and appearance as when received by Lessee (reasonable wear and tear
          excepted) and in good working order for the original intended purpose
          of the Equipment. If required the units of Equipment shall be
          deinstalled, disassembled and crated by an authorized manufacturer's
          representative or such other service person as is reasonably
          satisfactory to Lessor. Lessee shall remove installed markings that
          are not necessary for the operation, maintenance or repair of the
          Equipment. All Equipment will be cleaned, cosmetically acceptable, and
          in such condition as to be immediately installed into use in a similar
          environment for which the Equipment was originally intended to be
          used. All waste material and fluid must be removed from the Equipment
          and disposed of in accordance with then current waste disposal laws.
          Lessee shall return the units of Equipment to a location within the
          continental United States as Lessor shall direct. Lessee shall obtain
          and pay for a policy of transit insurance for the redelivery period in
          an amount equal to the replacement value of the Equipment. The transit
          insurance must name Lessor as the loss payee. The Lessee shall pay for
          all costs to comply with this section (a)."

     Subsection (b) is hereby amended and replaced with the following:

          "Until Lessee has fully complied with the requirements of Section 9(a)
          above, Lessee's rent payment obligation and all other obligations
          under this Agreement shall continue from month to month
          notwithstanding any expiration or termination of the lease term.
          During any such holdover rental period, Lessor may terminate the
          Lessee's right to use the Equipment upon ten (10) days notice to
          Lessee."

     Subsection (c) is hereby amended and replaced with the following:

          "At the expiration or termination of this Agreement or any Schedule,
          Lessee shall provide to Lessor a detailed inventory of all components
          of the Equipment including model and serial numbers. Lessee shall also
          provide an up-to-date copy of all other documentation pertaining to
          the Equipment. All service manuals, blue prints, process flow
          diagrams, operating manuals, inventory and maintenance records shall
          be given to Lessor at lease termination."

     10.  DEFAULT AND REMEDIES.

     Subsection (a) is hereby amended and replaced with the following:

          "Lessor may in writing declare this Agreement in default if: (i)
          Lessee breaches its obligation to pay rent or any other sum when due
          and fails to cure the breach within ten (10) days; (ii) Lessee
          breaches any of its insurance obligations under Section 8; (iii)
          Lessee breaches any of its other obligations under this Agreement or
          any Schedule and fails to cure that breach within thirty (30) days
          after written notice from Lessor; (iv) any representation or warranty
          made by Lessee in connection with this Agreement shall be false or
          misleading in any material respect when made; (v) Lessee or any
          guarantor or other obligor for the Lessee's obligations hereunder
          ("GUARANTOR") becomes insolvent or ceases to do business as a going
          concern; (vi) any Equipment is illegally used; (vii) if Lessee or any
          Guarantor is a natural person, any death or incompetency of Lessee or
          such Guarantor; or (viii) a petition is filed by or against Lessee or
          any Guarantor under any bankruptcy or insolvency laws and in the event
          of an involuntary petition, the petition is not dismissed within sixty
          (60) days of the filing date. The default declaration shall apply to
          all Schedules unless specifically excepted by Lessor."

     Subsection (b) is hereby amended and replaced with the following:

          "Upon the occurrence of a default, Lessor may, at its sole option,
          exercise one or more of the remedies set forth in this Section 10(b).
          After a default, at the request of Lessor, Lessee shall comply with
          the provisions of Section 9(a). Lessee hereby authorizes Lessor to
          peacefully enter any premises where any Equipment may be and take
          possession of the Equipment. Upon demand by the Lessor, Lessee shall
          immediately pay to Lessor as liquidated damages for loss of a bargain
          and not as a penalty, the Stipulated Loss Value of the Equipment and
          the Leasehold Improvements in each case, (calculated as of the rent
          payment date next succeeding the declaration of default), and all
          rents and other sums then due under this Agreement and all Schedules.
          Lessor may terminate this Agreement as to any or all of the Equipment.
          A termination shall occur only upon written notice by Lessor to Lessee
          and only as to the units of Equipment specified in any such notice.
          Lessor may, but shall not be required to, sell Equipment at private or
          public sale, in bulk or in parcels and without having the Equipment
          present at the place of sale. Lessor may also, but shall not be
          required to, lease, otherwise

<Page>

          dispose of or keep idle all or part of the Equipment. Lessor may use
          Lessee's premises for a reasonable period of time for any or all of
          the purposes stated above without liability for rent, costs, damages
          or otherwise. The proceeds of sale, lease or other disposition, if
          any, shall be applied in the following order of priorities: (i) to pay
          all of Lessor's costs, charges and expenses incurred in taking,
          removing, holding, repairing and selling, leasing or otherwise
          disposing of Equipment; then, (ii) to the extent not previously paid
          by Lessee, to pay Lessor all sums due from Lessee under this
          Agreement; then (iii) to reimburse to Lessee any sums previously paid
          by Lessee as liquidated damages; and then (iv) to Lessee, if there
          exists any surplus. Lessee shall immediately pay any deficiency in (i)
          and (ii) above."

     Subsection (c) is hereby amended and replaced with the following:

          "The foregoing remedies are cumulative, and any or all thereof may be
          exercised instead of or in addition to each other or any remedies at
          law, in equity, or under statute. If notice of any sale or other
          disposition hereunder by Lessor is required by applicable law, the
          parties agree that ten (10) days notice of any sale or disposition
          shall be considered commercially reasonable. Lessee shall pay Lessor's
          actual attorney's fees incurred in connection with the enforcement,
          assertion, defense or preservation of Lessor's rights and remedies
          under this Agreement, or if prohibited by law, such lesser sum as may
          be permitted. Waiver of any default shall not be a waiver of any other
          or subsequent default."

     11.  ASSIGNMENT.

     This section is hereby amended and replaced with the following:

          "LESSEE SHALL NOT SELL, TRANSFER, ASSIGN, ENCUMBER OR SUBLET ANY
          EQUIPMENT OR THE INTEREST OF LESSEE IN THE EQUIPMENT WITHOUT THE PRIOR
          WRITTEN CONSENT OF LESSOR, UNLESS LESSEE SUBLETS THE EQUIPMENT OR
          LEASEHOLD IMPROVEMENTS TO BIOTAGE, INC.. Lessor may, without the
          consent of Lessee, assign this Agreement, any Schedule or the right to
          enter into a Schedule. Lessee agrees that if Lessee receives written
          notice of an assignment from Lessor, Lessee will pay all rent and all
          other amounts payable under any assigned Schedule to such assignee or
          as instructed by Lessor. Lessee also agrees to confirm in writing
          receipt of the notice of assignment as may be reasonably requested by
          assignee. Lessee hereby waives and agrees not to assert against any
          such assignee any defense, set-off, recoupment claim or counterclaim
          which Lessee has or may at any time have against Lessor for any reason
          whatsoever."

     12.  NET LEASE.

     This section is hereby amended and replaced with the following:

          "Lessee is unconditionally obligated to pay all rent and other amounts
          due for the entire lease term no matter what happens, even if the
          Equipment or any Leasehold Improvement is damaged or destroyed, if it
          is defective or if Lessee no longer can use it. Lessee is not entitled
          to reduce or set-off against rent or other amounts due to Lessor or to
          anyone to whom Lessor assigns this Agreement or any Schedule whether
          Lessees claim arises out of this Agreement, any Schedule, any
          statement by Lessor, Lessors liability or any manufacturers liability,
          strict liability, negligence or otherwise."

     13.  INDEMNIFICATION.

     Subsection (a) is hereby amended and replaced with the following:

          "Lessee hereby agrees to indemnify Lessor, its agents, employees,
          successors and assigns (on an after tax basis) from and against any
          and all losses, damages, penalties, injuries, claims, actions and
          suits, including legal expenses, of whatsoever kind and nature arising
          out of or relating to the Equipment or the Leasehold Improvements or
          this Agreement, except to the extent the losses, damages, penalties,
          injuries, claims, actions, suits or expenses result from Lessors gross
          negligence or willful misconduct ("CLAIMS"). This indemnity shall
          include, but is not limited to, Lessor's strict liability in tort and
          Claims, arising out of (i) the selection, manufacture, purchase,
          acceptance or rejection of Equipment or Leasehold Improvements, the
          ownership of Equipment or Leasehold Improvements during the term of
          this Agreement, and the delivery, lease, possession, maintenance,
          uses, condition, return or operation of Equipment or Leasehold
          Improvements (including, without limitation, latent and other defects,
          whether or not discoverable by Lessor or Lessee and any claim for
          patent, trademark or copyright infringement or environmental damage)
          or (ii) the condition of Equipment or Leasehold Improvements sold or
          disposed of after use by Lessee, any sublessee or employees of Lessee.
          Lessee shall, upon request, defend any actions based on, or arising
          out of, any of the foregoing."

     14.  DISCLAIMER.

     This section is hereby amended and replaced with the following:

          "LESSEE ACKNOWLEDGES THAT IT HAS SELECTED THE EQUIPMENT AND LEASEHOLD
          IMPROVEMENTS WITHOUT ANY ASSISTANCE FROM LESSOR, ITS AGENTS OR
          EMPLOYEES. LESSOR DOES NOT MAKE, HAS NOT MADE, NOR SHALL BE DEEMED TO
          MAKE OR HAVE MADE, ANY
<Page>

          WARRANTY OR REPRESENTATION, EITHER EXPRESS OR IMPLIED, WRITTEN OR
          ORAL, WITH RESPECT TO THE EQUIPMENT AND LEASEHOLD IMPROVEMENTS LEASED
          UNDER THIS AGREEMENT OR ANY COMPONENT THEREOF, INCLUDING, WITHOUT
          LIMITATION, ANY WARRANTY AS TO DESIGN, COMPLIANCE WITH SPECIFICATIONS,
          QUALITY OF MATERIALS OR WORKMANSHIP, MERCHANTABILITY, FITNESS FOR ANY
          PURPOSE, USE OR OPERATION, SAFETY, PATENT, TRADEMARK OR COPYRIGHT
          INFRINGEMENT, OR TITLE. All such risks, as between Lessor and Lessee,
          are to be borne by Lessee. Without limiting the foregoing, Lessor
          shall have no responsibility or liability to Lessee or any other
          person with respect to any of the following: (i) any liability, loss
          or damage caused or alleged to be caused directly or indirectly by any
          Equipment or Leasehold Improvement, any inadequacy thereof, any
          deficiency or defect (latent or otherwise) of the Equipment or
          Leasehold Improvement, or any other circumstance in connection with
          the Equipment or Leasehold Improvement; (ii) the use, operation or
          performance of any Equipment or Leasehold Improvement or any risks
          relating thereto; (iii) any interruption of service, loss of business
          or anticipated profits or consequential damages; or (iv) the delivery,
          operation, servicing, maintenance, repair, improvement or replacement
          of any Equipment or Leasehold Improvement. If, and so long as, no
          default exists under this Agreement, Lessee shall be, and hereby is,
          authorized during the term of this Agreement to assert and enforce,
          whatever claims and rights Lessor may have against any Supplier of the
          Equipment or Leasehold Improvement at Lessee's sole cost and expense,
          in the name of and for the account of Lessor and/or Lessee, as their
          interests may appear."

     15.  REPRESENTATIONS AND WARRANTIES OF LESSEE.

     Subsection (a) is hereby amended and replaced with the following:

          "Lessee has adequate power and capacity to enter into, and perform
          under, this Agreement and all related documents (together, the
          "DOCUMENTS"). Lessee is duly qualified to do business wherever
          necessary to carry on its present business and operations, including
          the jurisdiction(s) where the Equipment is or is to be located, except
          where the failure to so qualify could not reasonably be expected to
          have a material adverse effect on the business or financial condition
          of the Lessee."

     Subsection (e) is hereby amended and replaced with the following:

          "There are no suits or proceedings pending or overtly threatened in
          writing in court or before any commission, board or other
          administrative agency against or affecting Lessee, which if decided
          against Lessee will have a material adverse effect on the ability of
          Lessee to fulfill its obligations under this Agreement."

     Subsection (g) is hereby amended and replaced with the following:

          "Each financial statement delivered to Lessor has been prepared in
          accordance with generally accepted accounting principles consistently
          applied. Since the date of the most recent financial statement, there
          has been no material adverse change in the financial condition of the
          Lessee."

     16.  OWNERSHIP FOR TAX PURPOSES, GRANT OF SECURITY INTEREST; USURY SAVINGS.

     Subsection (a) is hereby amended and replaced with the following:

          "For income tax purposes, the parties hereto agree that it is their
          mutual intention that Lessee shall be considered the owner of the
          Equipment. Accordingly, Lessor agrees (i) to treat Lessee as the owner
          of the Equipment on its federal income tax return, (ii) not to take
          actions or positions inconsistent with such treatment on or with
          respect to its federal income tax return, and (iii) not to claim any
          tax benefits available to an owner of the Equipment on or with respect
          to its federal income tax return. The foregoing undertakings by Lessor
          shall not be violated by Lessor's taking a tax position inconsistent
          with the foregoing sentence to the extent such a position is required
          by law or is taken through inadvertence so long as such inadvertent
          tax position is reversed by Lessor promptly upon its discovery. Lessor
          shall in no event be liable to Lessee if Lessee fails to secure any of
          the tax benefits available to the owner of the Equipment, unless such
          failure is caused by Lessor's failure to comply with this Section
          16(a)."

     Subsection (b) is hereby amended and replaced with the following:

          "Lessee hereby grants to Lessor a first security interest in the
          Equipment, together with all additions, attachments, accessions,
          accessories and accessions thereto whether or not furnished by the
          Supplier of the Equipment and any and all substitutions, replacements
          or exchanges therefor, and any and all insurance and/or other proceeds
          of the property in and against which a security interest is granted
          hereunder. Notwithstanding anything to the contrary contained
          elsewhere in this Agreement, to the extent that Lessor asserts a
          purchase money security interest in any items of Equipment ("PMSI
          EQUIPMENT"): (i) the PMSI Equipment shall secure only those sums which
          have been advanced by Lessor for the purchase

<Page>

          of the PMSI Equipment, or the acquisition of rights therein, or the
          use thereof (the "PMSI INDEBTEDNESS"), and (ii) no other Equipment
          shall secure the PMSI Indebtedness. Notwithstanding anything to the
          contrary set forth in this Agreement or any Schedule, Lessor
          acknowledges and agrees that (i) Lessor is merely financing the cost
          of the Leasehold Improvements on behalf of Lessee and is not leasing
          them to Lessee and in no event shall Lessor be deemed to have any
          ownership or other interest in the Leasehold Improvements and (ii) in
          no event shall the Equipment include, and the Lessee shall not be
          deemed to have granted to Lessor a security interest in, any rights,
          interests or property to the extent that such a grant would, under the
          terms of the MIT Lease (as hereinafter defined) result in a breach of
          the terms of, or constitute a default under, or cause a termination of
          the MIT Lease. As used herein, the term "MIT Lease" means that certain
          Indenture of Lease dated as of June 13, 2001 between Lessee, as
          Tenant, and Massachusetts Institute of Technology, as Landlord, as it
          may be amended, supplemented, extended or replaced from time to time."

     17.  EARLY TERMINATION.

     Subsection (c) is hereby amended and replaced with the following:

          "If all amounts due hereunder have been paid on the Termination Date,
          Lessor shall (i) sell the Equipment on an AS IS BASIS for cash to the
          highest bidder and (ii) refund the proceeds of such sale (net of any
          related expenses) to Lessee up to the amount of the Termination Value.
          If such sale is not consummated within twelve (12) months, no
          termination shall occur and Lessor shall refund the Termination Value
          (less any expenses incurred by Lessor) to Lessee."

     19.  EARLY TERMINATION.

     This section is hereby amended and replaced with the following:

          "Lessee may, at lease expiration, purchase all (but not less than all)
          of the Equipment on any Schedule on an AS IS BASIS for cash equal to
          the amount indicated on such Schedule (the "OPTION PAYMENT"), plus all
          applicable sales taxes. The Option Payment, plus all applicable sales
          taxes, shall be due and payable in immediately available funds on the
          expiration date of such Schedule. Unless the Option Payment under a
          Schedule is $1.00, Lessee must notify Lessor of its intent to purchase
          the Equipment subject to such Schedule in writing at least one hundred
          eighty (180) days prior to the expiration date of the Schedule. If
          Lessee is in default, or if the Schedule or this Agreement has already
          been terminated, Lessee may not purchase the Equipment."

     20.  MISCELLANEOUS.

     Subsection (a) is hereby amended and replaced with the following:

          "LESSEE AND LESSOR UNCONDITIONALLY WAIVE THEIR RIGHTS TO A JURY TRIAL
          OF ANY CLAIM OR CAUSE OF ACTION BASED UPON OR ARISING OUT OF THIS
          AGREEMENT, ANY OF THE RELATED DOCUMENTS, ANY DEALINGS BETWEEN LESSEE
          AND LESSOR RELATING TO THE SUBJECT MATTER OF THIS TRANSACTION OR ANY
          RELATED TRANSACTIONS. THE SCOPE OF THIS WAIVER IS INTENDED TO BE ALL
          ENCOMPASSING OF ANY AND ALL DISPUTES THAT MAY BE FILED IN ANY COURT.
          THIS WAIVER IS IRREVOCABLE. THIS WAIVER MAY NOT BE MODIFIED EITHER
          ORALLY OR IN WRITING. THE WAIVER ALSO SHALL APPLY TO ANY SUBSEQUENT
          AMENDMENTS, RENEWALS, SUPPLEMENTS OR MODIFICATIONS TO THIS AGREEMENT,
          ANY RELATED DOCUMENTS, OR TO ANY OTHER DOCUMENTS OR AGREEMENTS
          RELATING TO THIS TRANSACTION OR ANY RELATED TRANSACTION. THIS
          AGREEMENT MAY BE FILED AS A WRITTEN CONSENT TO A TRIAL BY THE COURT."

     Subsection (e) is hereby amended and replaced with the following:

          "Any rent or other amount not paid to Lessor within ten (10) days
          after the date when due shall bear interest, from the date which is
          ten (10) days after the due date until paid, at the lesser of eighteen
          percent (18%) per annum or the maximum rate allowed by law. Any
          provisions in this Agreement and any Schedule that are in conflict
          with any statute, law or applicable rule shall be deemed omitted,
          modified or altered to conform thereto."

     Subsection (h) is hereby deleted in its entirety.

     Subsection (i) is now known as subsection (h).

     TERMS USED, BUT NOT OTHERWISE DEFINED HEREIN SHALL HAVE THE MEANINGS GIVEN
TO THEM IN THE AGREEMENT. EXCEPT AS EXPRESSLY AMENDED HEREBY, THE AGREEMENT
SHALL REMAIN IN FULL FORCE AND EFFECT.

<Page>

IF THERE IS ANY CONFLICT BETWEEN THE PROVISIONS OF THE AGREEMENT AND THIS
AMENDMENT, THEN THIS AMENDMENT SHALL CONTROL.

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment
simultaneously with the Agreement by signature of their respective authorized
representative set forth below.

GENERAL ELECTRIC CAPITAL CORPORATION         DYAX CORP.


By: /s/ John Edel                            By:  /s/ Stephen S. Galliker
    -----------------------------------           ------------------------------

Name: John Edel                              Name: Stephen S. Galliker
      ---------------------------------            -----------------------------

Title: Senior Vice President                 Title: Executive Vice President
       --------------------------------             ----------------------------

<Page>

                  CROSS-COLLATERAL AND CROSS-DEFAULT AGREEMENT

General Electric Capital Corporation
401 Merritt 7 2nd Floor
Norwalk, CT 06856

Gentlemen:

     You (and/or your successors or assigns, "YOU") have entered into or
purchased one or more conditional sale contracts, lease agreements, chattel
mortgages, security agreements, notes and other choses in action (herein
designated "ACCOUNTS") arising from the bona fide sale or lease to us, by
various vendors or lessors, of equipment described in the agreements evidencing
such Accounts (herein designated "COLLATERAL") and/or you have made direct loans
to or otherwise extended credit to us evidenced by Accounts creating security
interests in Collateral.

     In order to induce you to extend our time of payment on one or more
Accounts and/or to make additional loans to us and/or to purchase additional
Accounts and/or to lease us additional equipment, and in consideration of you so
doing, and for other good and valuable consideration, the receipt of which we
hereby acknowledge, we agree as follows:

     All presently existing and hereafter acquired Collateral in which you have
or shall have a security interest shall secure the payment and performance of
all of our liabilities and obligations to you of every kind and character,
whether joint or several, direct or indirect, absolute or contingent, due or to
become due, and whether under presently existing or hereafter created Accounts
or agreements, or otherwise.

     We further agree that your security interest in the property covered by any
Account now held or hereafter acquired by you shall not be terminated in whole
or in part until and unless all indebtedness of every kind, due or to become
due, owed by us to you is fully paid and satisfied and the terms of every
Account have been fully performed by us. It is further agreed that you are to
retain your security interest in all property covered by all Accounts held or
acquired by you, as security for payment and performance under each such
Account, notwithstanding the fact that one or more of such Accounts may become
fully paid. However, when all of the obligations evidenced by the Accounts have
been paid in full, your security interest in the Collateral shall terminate and,
by your acceptance of this instrument, you agree to execute appropriate releases
of liens on the Collateral at our request and expense.

     This instrument is intended to create cross-default and cross-security
between and among all the within described Accounts now owned or hereafter
acquired by you.

     A default under any Account shall be deemed to be a default under all other
Accounts.

     All rights granted to you hereunder shall be cumulative and not
alternative, shall be in addition to and shall in no manner impair or affect
your rights and remedies under any existing Account, agreement, statute or rule
of law.

     This agreement may not be varied or altered nor its provisions waived
except by your duly executed written agreement. This agreement shall inure to
the benefit of your successors and assigns and shall be binding upon our heirs,
administrators, executors, legal representatives, successors and assigns.

     Notwithstanding anything to the contrary set forth in this Cross-Collateral
and Cross-Default Agreement, or any Account, by your acceptance of this
instrument, you acknowledge and agree that in no event shall the Collateral
include, and we shall not be deemed to have granted to you a security interest
in, any Leasehold Improvements or any rights, interests or property to the
extent that such a grant would, under the terms of the MIT Lease, result in a
breach of the terms of, or constitute a default under or cause a termination of,
the MIT Lease. Capitalized terms used but not otherwise defined herein shall
have the meanings attributed to them in that certain Master Lease Agreement
dated as of May 1, 2001 between you and the undersigned.

     IN WITNESS WHEREOF, this agreement is executed this 1st day of May, 2001.

<Page>

                       DYAX CORP.
                       (Name of Proprietorship, Partnership or
                        Corporation, as applicable)

                       By: /s/ Stephen S. Galliker
                           ---------------------------------------------

                                    (Signature)


                       Title: Executive Vice President
                              ------------------------------------------

                                    (Owner, Partner or Officer, as applicable)

                       Address: One Kendall Square Building 600,
                                Cambridge, MA 02139