1

                           DISTRIBUTORSHIP AGREEMENT

     This Agreement (the "Agreement") is made and entered into this
11th day of March, 1996, by and among INVITRO INTERNATIONAL, a
California corporation ("INVITRO") having its principal office at
16632 Millikan Avenue, Irvine, California 92714, and MIRAGEN INC., a
California corporation ("MIRAGEN") having its principal office at
10005 Muirlands, Suite O, Irvine, California 92718.

                        RECITALS AND CERTAIN DEFINITIONS

     A.   MIRAGEN has developed and owns proprietary rights to a
product line named the "Guardian DNA system(TM)" (such system,
including future modifications and/or improvements made by either of
the parties hereto, is called the "Guardian DNA Product Line" and such
products are herein called the "Guardian DNA Products").  As currently
configured, the Guardian DNA system consists of a DNA sample
acquisition kit, annually updated emergency information package, a
child safety video tape and a mailer for a precoded sample tube.  A
buccal sample (epithelial cells extracted from the inside of the
mouth) is collected from a child with a cotton swab and placed in the
pre-coded tube.  The tube with the sample is then mailed to MIRAGEN,
where it is stored in a preservative solution in MIRAGEN's secure
freezer for up to 16 years.  Anonymity of the sample is ensured
because no names or social security numbers are used.  The child's
parents retain the matching code number.  If there is a need for an
identification after notification by a law enforcement agency, MIRAGEN
will perform a DNA test to determine if there is a positive
identification.

     B.   INVITRO is engaged in the marketing and sale of products
relating to human health care and wishes to act as an exclusive
distributor of the Guardian DNA product line to Institutions
throughout the world on a basis demonstrating to MIRAGEN that INVITRO
has the capacity to sell the Guardian DNA Product Line in significant
volumes and in a manner that will preserve and enhance the reputation
and goodwill associated with the Guardian DNA Product Line.  For the
purposes of this Agreement, the term "Institutional Markets" shall
mean Institutions, birthing facilities, and all similar obstetric
facilities providing for delivery of newborn infants.  The term
"Territory" shall mean all geographic markets throughout the world.

     C.   MIRAGEN desires to appoint INVITRO as the exclusive
distributor, upon the terms and conditions set forth herein, to market
and sell the Guardian DNA Product Line to Institutional Markets
throughout the Territory.

     NOW, THEREFORE, in consideration of the mutual promises below,
the parties agree as follows:

  2

SECTION 1.     APPOINTMENT AS DISTRIBUTOR AND TRADEMARK LICENSE

     1.1. DISTRIBUTION RIGHTS.   MIRAGEN appoints INVITRO as the
exclusive distributor for sale of the Guardian DNA Product Line to
Institutional Markets in the Territory as long as performance
standards set forth in Section 8 of this Agreement are met by INVITRO,
and INVITRO accepts such appointment subject to the terms and
conditions set forth herein.  For the term of this Agreement, MIRAGEN
further grants INVITRO a nonexclusive right and license to use the
trade name and trademark "Guardian DNA" and to use the patent rights
of MIRAGEN in connection with the marketing, sale and distribution of
Guardian DNA Products by INVITRO to the Institutional Markets.

     1.2. INDEPENDENT DISTRIBUTOR.  Each party is an independent
contractor under this Agreement and neither has, nor will have, any
power, right or authority, nor will it represent that it has any
power, right or authority, to bind the other party, or to assume or to
create any obligations or responsibility, express or implied, on
behalf of the other party.  Nothing stated in this Agreement shall be
construed as constituting INVITRO and MIRAGEN as partners, joint
venturers or as creating relations of employer and employee, master
and servant, or principal and agent between the parties to this
Agreement.

     1.3. RIGHT TO PURCHASE DISTRIBUTE THE PRODUCT LINE.   This
Agreement gives INVITRO the right to purchase the MIRAGEN Product Line
from MIRAGEN, and to resell the MIRAGEN Product Line to purchasers and
customers in Institutional Markets within the Territory in accordance
with the terms of this Agreement.  INVITRO's compensation will come
from the margin between the price it pays MIRAGEN for the products
covered hereby and the price at which INVITRO sells those products to
customers in the Institutional Markets, and MIRAGEN shall not be
obligated to pay any compensation to INVITRO.  Collection of accounts
receivable for Guardian DNA Products sold by INVITRO to customers in
the Institutional Market shall be at the sole risk of INVITRO and
failure to collect the same shall not alter the obligation of INVITRO
to make payment for said Guardian DNA Products to MIRAGEN under the
terms of this Agreement.

SECTION 2.  TERM

     2.1. This Agreement shall take effect on the date first written
above and shall be for a term of three (3) years from the date written
above unless earlier terminated pursuant to Sections 5.1.2, 8 or 11.  
This Agreement shall automatically renew for additional consecutive
one (1) year terms unless at least 90 days before the end of any term
either party notifies the others of its decision not to renew due to:

  3

     (a)  a failure to establish prices to be effective for the
          following year pursuant to the provisions of Section 5.1.2,
          or

     (b)  a failure by INVITRO to order and purchase minimum purchase
          quotas required by Section 8, or

     (c)  a material default by the other party of one or more of its
          obligations under this Agreement.

INVITRO shall not be entitled to any payments or any kind due to
expiration of the term of this Agreement, termination of this
Agreement pursuant to Sections 5.1.2, 8 or 11, or failure to renew or
extend this Agreement.

SECTION 3.  INVITRO'S OBLIGATIONS

     3.1. BEST EFFORTS.   INVITRO agrees to use its best efforts to
sell the Guardian DNA Products to customers in the Institutional
Markets and to encourage the purchase of Guardian DNA Products by
INVITRO's Institutional Market customers in the Territory.   INVITRO
shall use the Guardian DNA trade name and trademark in promoting the
sale and marketing of the Guardian DNA Products and shall not use any
other trade name or trademarks in such activities without first
obtaining the prior written consent of MIRAGEN, which may be granted
or withheld by MIRAGEN for any reason.   INVITRO acknowledges that the
Guardian DNA trade name and trademarks are the property of MIRAGEN and
INVITRO shall discontinue the use of such trade name and trademarks in
the event this Agreement is terminated for any reason.

     3.2. SALES FORCE.   INVITRO agrees to employ and maintain
knowledgeable full-time sales and distribution personnel to market,
sell and distribute Guardian DNA Products hereunder throughout the
United States and in such other areas as INVITRO shall determine. 
INVITRO's sales staff will obtain and maintain knowledge and expertise
concerning the Guardian DNA Product Line that is reasonably
satisfactory to MIRAGEN and INVITRO.

     3.3. REGULATORY APPROVAL.   INVITRO shall be responsible for
determining whether any governmental regulatory approvals are required
for it to market and sell the Guardian DNA Products in any
jurisdiction within the Territory and to determine all packaging and
labeling requirements imposed by governmental prescriptions for the
state, province and country of destination designated by INVITRO for
sale and delivery of the Guardian DNA Products. MIRAGEN agrees that it
will comply with any and all instructions and specifications provided
to MIRAGEN in writing by INVITRO concerning the packaging and labeling
of Guardian DNA Products sold by MIRAGEN to INVITRO hereunder.

  4

     3.4. PRIOR APPROVAL OF ADVERTISING AND MARKETING MATERIALS. 
INVITRO shall submit to MIRAGEN for its approval in advance, which
shall not be unreasonably withheld, samples of all advertising,
promotional materials and protocols that INVITRO desires to use to
promote the Guardian DNA Products that have not been prepared or
previously approved by MIRAGEN, including without limitation,
translations of materials into the English language where applicable.

     3.5. COSTS OF ADVERTISING.  All costs of advertising Guardian DNA
Products for Institutional Markets throughout the Territory incurred
by INVITRO shall be borne by INVITRO.

     3.6. INITIAL STOCKING ORDER.  Upon execution of this Agreement
and as a condition precedent to the effectiveness of this Agreement,
INVITRO shall place an initial purchase order for at least 10,000
units of the Guardian DNA Product Line for the Institutional Markets,
to be delivered to INVITRO by MIRAGEN within two months of the date of
this Agreement.

     3.7. REQUIREMENTS.   During the term of this Agreement, INVITRO
agrees to purchase from MIRAGEN all of INVITRO's requirements of all
components included in the Guardian DNA Product Line, including
without limitation all of INVITRO's requirements of DNA sample
acquisition kits, emergency information packages, child safety video
tapes and mailers for precoded sample tubes.  All Guardian DNA
Products sold by INVITRO shall include a specification that samples
are to be returned by mail to MIRAGEN for storage at MIRAGEN.

     3.8. ACTIVITIES OUTSIDE INSTITUTIONAL MARKET.   INVITRO shall not
solicit orders for Guardian DNA Products from customers outside the
Institutional Markets, and shall not compete with the activities of
MIRAGEN or its distributors and sales representatives for the sale of
Guardian DNA Products to markets and through channels of distribution
other than the Institutional Markets. In the event INVITRO receives
unsolicited orders for Guardian DNA Products from customers outside
the Institutional Markets, INVITRO agrees to promptly refer the same
to MIRAGEN.

     3.9. NO COMPETITION.  During the term of this Agreement, INVITRO
shall not, nor shall it permit any of its affiliates to, engage in the
marketing, promotion, sale, distribution, development or manufacturing
of any products which are competitive with the Guardian DNA Product
Line except for any improvements or modifications to Guardian DNA
Products developed by INVITRO for which all right, title and interest
are transferred by INVITRO to MIRAGEN.   For a period of twelve (12)
months following any termination of this Agreement, INVITRO covenants
and agrees that it shall not, nor shall it permit any of its
affiliates to, engage in the marketing, promotion, sale, distribution,
development or manufacturing of any products which are competitive
with the Guardian DNA Product Line in the Institutional Markets.

  5

SECTION 4.  OBLIGATIONS OF MIRAGEN

     4.1. SALE OF PRODUCTS AND PRESERVATION OF SAMPLES.

          (a)  During the term of this Agreement, MIRAGEN agrees to
sell Guardian DNA Products to INVITRO pursuant to orders MIRAGEN
receives from INVITRO for the Institutional Markets in the Territory
in accordance with this Agreement.

          (b)  During the term of this Agreement and after the
expiration of this Agreement, MIRAGEN further covenants and agrees to
maintain and preserve in its secure freezer all samples mailed or
otherwise delivered to MIRAGEN resulting from the sale and use of
Guardian DNA Products sold by INVITRO for a period of at least 16
years from and after the date each such sample was first received by
MIRAGEN.

     4.2. TECHNICAL SUPPORT.  MIRAGEN agrees to provide INVITRO with
reasonable technical support and advice for marketing the Guardian DNA
Product Line and to provide INVITRO's staff with training necessary to
demonstrate use of the Guardian DNA Product Line.

SECTION 5.  PRICES AND SHIPMENT

     5.1. PRICES.

          5.1.1.    FIRST YEAR.  During the first year of this
Agreement, MIRAGEN will sell the Guardian DNA Products to INVITRO, at
the unit prices stipulated in EXHIBIT "A" attached to this Agreement.

          5.1.2.    SECOND AND SUCCESSIVE YEARS.  At least 120 days
before each anniversary of the date of this Agreement unless it shall
have been earlier terminated pursuant to other provisions hereof,
MIRAGEN will provide INVITRO with the prices for all products in the
Guardian DNA Product Line for the following year of this Agreement
which shall include an adjustment for any increases in costs incurred
by MIRAGEN after the date hereof and a profit margin to MIRAGEN
consistent with its initial product margin hereunder.  In the event
INVITRO objects to any of such prices, the parties shall negotiate in
good faith in order to determine the prices to apply for such
following year.  If the parties are unable to reach agreement at least
90 days prior to the anniversary of the date of this Agreement as to
the prices to apply to purchases of Guardian DNA Products by INVITRO
under this Agreement during the following year, this Agreement shall
automatically terminate on such anniversary date.  In the event of
termination of this Agreement pursuant to the terms of the preceding
sentence, MIRAGEN shall not, within twelve (12) months after the
termination of this Agreement, enter into agreements for the sale and
distribution of the Guardian DNA Product Line in the Institutional
Market if such agreements provide for prices to be paid to MIRAGEN
that are less than the last prices offered to INVITRO in negotiations
pursuant to this Section 5.1.2.

  6

     5.2. PRICING TERMS.  All prices are F.O.B. Irvine, California,
U.S.A., and are stated and payable in United States Dollars.   Unit
prices for any particular product within the Guardian DNA Product Line
are those stipulated in EXHIBIT "A" attached to this Agreement as the
same may be amended from time to time in accordance with Section 5.1.2
above and the agreement of the parties.

     5.3. SHIPPING TERMS.  INVITRO will normally request MIRAGEN to
ship the Guardian DNA Products to INVITRO's warehouse facilities in
Irvine, California.  At the election of INVITRO, the parties
acknowledge that INVITRO from time to time may elect to request that
MIRAGEN send shipments of Guardian DNA Products directly to INVITRO's
customers in the Institutional Markets or to warehouse locations in
INVITRO's distribution network designated by INVITRO, in which event
freight, insurance in transit and other shipping costs shall be
reimbursed by INVITRO to MIRAGEN.   Drop shipments made at INVITRO's
request shall be made on INVITRO's behalf and at INVITRO's expense,
and INVITRO authorizes MIRAGEN under such circumstances to chose a
carrier, arrange for transport of the goods to INVITRO's customer or
INVITRO's marketing network in the appropriate country within the
Territory where the use of the Guardian DNA Products is expected to
occur, and to insure the goods during shipment for the account of
INVITRO.  The risk of loss on all shipments is with INVITRO upon
delivery by MIRAGEN to a carrier F.O.B. Irvine, California, U.S.A.

SECTION 6.  PURCHASE ORDERS; FORECASTS

     6.1.   PURCHASE ORDERS.    All orders must be made in writing and
shall be effected by INVITRO's issuance of purchase order forms
designated by MIRAGEN, which shall be subject to the terms and
conditions of this Agreement, sent by mail, courier delivery, personal
delivery, telex or facsimile transmission.  Each purchase order shall
contain the quantity of Guardian DNA Products for the Institutional
Market purchased, delivery date(s), dating, routing instructions,
destination, country of intended use and sale, and confirmation of
price.  For accounting convenience, each purchase order shall bear a
separate number having no numerical relationship to this Agreement. 
Each purchase order, however, shall make specific reference to this
Agreement and thereby incorporate the terms of this Agreement.   No
term or condition contained in any such purchase order shall alter,
amend, modify or supplement the obligations of MIRAGEN hereunder
unless specifically agreed to in writing by MIRAGEN.  All orders are
subject to acceptance by MIRAGEN at its headquarters, and MIRAGEN
promptly will send INVITRO a written acknowledgment of all accepted
orders.  MIRAGEN reserves the right to charge INVITRO a change or
cancellation fee for any change or cancellation of 25% or more in a
previously accepted order.  MIRAGEN shall not be deemed to be in
breach of this Agreement for failure to fill an order due to economic
or other factors beyond its direct control including strikes, lack of
raw material, or substantial cost increases therefor.

  7

     6.2. QUANTITIES.  INVITRO agrees that all orders shall be placed
no less than 30 days in advance of the requested delivery date. 

     6.3. FORECASTS.  INVITRO shall provide MIRAGEN every three months
with a six-month rolling forecast for units of the Guardian DNA
Product Line for the Institutional Market in order that MIRAGEN may
organize its inventories.  

SECTION 7.      PAYMENT.

     7.1.   INVITRO shall pay MIRAGEN the full purchase price and any
costs MIRAGEN incurs on INVITRO's behalf for an order within 30 days
after shipment by MIRAGEN.

SECTION 8.   MINIMUM PURCHASE QUOTAS

     8.1. FIRST THREE YEARS.  So long as this Agreement has not been
terminated, and as a condition to maintaining exclusive distribution
rights to the Institutional Market, INVITRO will purchase the
following minimum quantities of the Guardian DNA Products from MIRAGEN
during the time periods indicated:

Period - First Year of this Agreement:
- --------------------------------------
Each month during the First Three Months
      of this Agreement                          3,333 Units
Each month during the Second Three Months
      of this Agreement                          3,333 Units
Each month during the Third Three Months
      of this Agreement                         10,000 Units
Each month during the Fourth Three Months
      of this Agreement                         20,000 Units

Period - Second Year of this Agreement:
- ---------------------------------------
Each month during the First Six Months of the
     Second Year of this Agreement              25,000 Units
Each month during the Last Six Months of the
     Second Year of this Agreement              30,000 Units

Period - Third Year of this Agreement:
- --------------------------------------
Each month during the First Six Months of the
     Third Year of this Agreement               40,000 Units
Each month during the Last Six Months of the
     Third Year of this Agreement               50,000 Units

In the event INVITRO shall fail to purchase the minimum number of
Units required hereunder for a period of two consecutive months or for
any three months within a period of 12 consecutive months, MIRAGEN
shall have the right of terminating this Agreement upon 90 days' prior
written notice to INVITRO.

     However, in the event that any order placed with MIRAGEN is not
delivered within the period required by this Agreement, INVITRO will
have an opportunity to deliver a new forecast with new minimums for
the foregoing time periods in which INVITRO is required to purchase
minimum quotas.

  8

     8.2. SUBSEQUENT YEARS.  INVITRO shall establish minimum purchase
quotas for subsequent years after the third year of this Agreement for
the Institutional Markets within the Territory by agreement with
MIRAGEN.  If the parties are unable to reach agreement at least 30
days prior to the anniversary of the date of this Agreement as to the
minimum quotas to apply to purchases of product by INVITRO under this
Agreement during the following year, this Agreement shall
automatically terminate on such anniversary date, and MIRAGEN shall
not, within twelve (12) months after the termination of this
Agreement, enter into any agreements for the distribution and sale of
Guardian DNA Products to Institutional Markets in the Territory if
such agreements provide for prices and minimum quantities that are
less than the last prices and minimum quantities offered to INVITRO in
negotiations pursuant to this Section 8.2 and Section 5.1.2 of this
Agreement.

SECTION 9.   PATENT AND TRADEMARK PROTECTION

     9.1.   INVITRO acknowledges that trade names, trademarks, patents
and patent applications of MIRAGEN applicable to products in the
Guardian DNA Product Line are the sole property of MIRAGEN.  INVITRO
shall not use the trademark "Guardian DNA" or any other trademarks of
MIRAGEN except in the normal course of advertising or selling the
Guardian DNA Product Line pursuant to this Agreement and then only in
a manner approved by MIRAGEN.  During the term of this Agreement,
INVITRO will immediately inform MIRAGEN by written notice of any
infringement of the trademarks or patent rights of MIRAGEN that
INVITRO becomes aware of and, at MIRAGEN's request and expense, will
cooperate with MIRAGEN in any action it deems necessary to protect its
trademarks and patent rights against such infringement.

SECTION 10.     WARRANTY AND DISCLAIMER

     10.1.     MIRAGEN WARRANTS THAT GUARDIAN DNA PRODUCTS DELIVERED
BY IT PURSUANT TO THIS AGREEMENT WILL BE (i) MANUFACTURED, ASSEMBLED,
LABELED AND PACKAGED IN ACCORDANCE WITH WRITTEN SPECIFICATIONS
MUTUALLY ACCEPTABLE TO MIRAGEN AND INVITRO, (ii) FREE FROM
COMMERCIALLY UNACCEPTABLE CONTAMINATES IN MATERIALS RESULTING FROM
MANUFACTURING AND ASSEMBLY OPERATIONS, (iii) FREE FROM MATERIAL
DEFECTS IN WORKMANSHIP, AND (iv) OF GOOD AND MERCHANTABLE QUALITY AND
SAFE AND FIT FOR THEIR INTENDED USE AND PURPOSE AS DNA IDENTIFICATION
TESTS.

Guardian DNA Products that do not conform will be replaced by MIRAGEN
without charge to INVITRO.

     10.2.     THE ABOVE WARRANTIES ARE EXPRESSLY MADE IN LIEU OF ALL
OTHER WARRANTIES OR OBLIGATIONS, EXPRESS OR IMPLIED, BY MIRAGEN AS TO
PRODUCTS DELIVERED IN ACCORDANCE WITH THIS AGREEMENT.   MIRAGEN
DISCLAIMS ALL IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE EXCEPT FOR THE EXPRESS WARRANTIES SET FORTH ABOVE.

  9

SECTION 11.   TERMINATION

     11.1.     TERMINATION FOR CAUSE.  Any party may terminate this
Agreement for just cause:  (a) upon any material breach of this
Agreement by the other party if the breach is not cured within forty-
five (45) days' written notice of the breach or; (b) immediately upon
the other party's insolvency, bankruptcy, suspension of business,
assignment of assets for the benefit of creditors, voluntary
dissolution, or appointment of a trustee for all or a substantial
portion of the other party's assets.

     11.2.     FAILURE TO MEET MINIMUM QUOTAS OR PAYMENT.    MIRAGEN
may terminate this Agreement immediately upon INVITRO's failure to
make the minimum purchases required by Section 8, or if INVITRO shall
fail to make any payments due under this Agreement if payment is not
cured within thirty (30) days' written notice of default.

     11.3.     FAILURE TO RENEW.  This Agreement may be terminated
pursuant to the provisions of Section 5.1.2.

     11.4.     SURVIVAL.  Upon termination or expiration of the term
of this Agreement, the rights and obligations of the parties under
this Agreement shall end, and neither party shall have any claim,
including any claim for termination damages, against the other;
provided, however, that obligations which by their terms are
continuing obligations of this Agreement shall survive termination of
this Agreement and shall be binding on the parties thereafter.

12.  TAXES, DUTIES, IMPORT PERMITS, COMPLIANCE WITH LAW, APPROVALS

     12.1.     TAXES, DUTIES, PERMITS, APPROVALS.  INVITRO shall have
the sole responsibility to pay all import duties and fees, taxes and
other charges levied by government authorities in the Territory upon
or in connection with any transaction covered by this Agreement,
including, without limitation, taxes on sales, use, transactions or
inventory, and value added taxes.  INVITRO shall have the sole
responsibility to obtain all permits, licenses and approvals from
governmental authorities necessary to import and sell the Guardian DNA
Products in various jurisdictions in the Territory.  If any government
authority or judicial body invalidates any portion of this Agreement,
MIRAGEN shall have the option to terminate this Agreement immediately,
by written notice to INVITRO, for such jurisdiction only where
governmental or judicial invalidation shall have occurred.

     12.2.     COMPLIANCE WITH LAW. INVITRO shall comply, and cause
its sales personnel to comply, with all applicable laws and
regulations in the Territory, including advertising laws. In order for
INVITRO to obtain and maintain any and all permits, certificates or
licenses necessary for the proper conduct of INVITRO's duties and
obligations under this Agreement,  MIRAGEN shall fully comply with
labeling prescriptions and laws applicable in the Territory where
products in the Product

  10

Line are destined for use and consumption, as from time to time
communicated by INVITRO to MIRAGEN.

SECTION 13.   CONFIDENTIAL INFORMATION

     13.1.     ACCESS TO INFORMATION.  INVITRO acknowledges that
during the term of this Agreement it may have access to proprietary
information, trade secrets, and other confidential information of
MIRAGEN, that such information is a valuable asset of MIRAGEN, and
that its disclosure or unauthorized use will cause substantial harm to
MIRAGEN.  As used in this Agreement, the term "Confidential
Information" means: (a) proprietary information of MIRAGEN; (b)
information marked or designated by MIRAGEN as confidential; (c)
information, whether or not in written form and whether or not
designated as confidential, which is known to INVITRO as being treated
by MIRAGEN as confidential; and (d) information provided to MIRAGEN by
third parties which MIRAGEN is obligated to keep confidential.

     13.2.     NONDISCLOSURE AND NON-USE.  INVITRO agrees that it will
not disclose to others or use any Confidential Information, unless and
until, and then only to the extent that, such items become available
to the public, other than by any act or failure on the part of INVITRO
to prevent accidental or negligent loss or release to any unauthorized
person of the Confidential Information.

     13.3.     REMEDIES.  Notwithstanding the provisions of Section 14
requiring arbitration of disputes, in the event of the breach by
INVITRO of the terms of this Section 13, MIRAGEN shall be entitled to
specific performance, including immediate issuance of a temporary
restraining order or preliminary injunction, and to any other remedies
provided by applicable law in the event of a breach by INVITRO of the
provisions of this Section 13.

     13.4.     DURATION.  The obligations set forth in this Section 13
will continue beyond the term of this Agreement for a period of three
(3) years.

  11

SECTION 14.  GENERAL PROVISIONS

     14.1.     NON-ASSIGNMENT.  INVITRO will not assign, transfer, or
sell the rights under this Agreement, or delegate its duties
hereunder, without the prior written consent of MIRAGEN.  A transfer
of a controlling interest in INVITRO shall constitute an assignment
for this purpose.  MIRAGEN will not assign, transfer, or sell its
rights to this Agreement or delegate its duties hereunder without the
prior written consent of INVITRO except to a successor in connection
with the sale of substantially all of its assets, merger or
consolidation of MIRAGEN with another corporate entity.  This
Agreement shall inure to the benefit of the successors of the
respective parties hereto.

     14.2.     ENTIRE AGREEMENT; MODIFICATIONS.   This Agreement
contains the entire agreement between the parties as to the subject
matter hereof, and unless otherwise provided in this Agreement, no
modification or waiver of any of the provisions, or any future 
representation, promise, or addition shall be binding upon the parties
unless made in writing and signed by the parties affected.  The terms
and conditions of this Agreement will prevail over any inconsistent or
additional terms contained in INVITRO's purchase orders to products or
any other documents.

     14.3.     WAIVER.  MIRAGEN may waive in writing any obligation
INVITRO has under this Agreement, but such a waiver will not affect
its right to require strict compliance with this Agreement in the
future.

     14.4.     INDEMNIFICATION BY INVITRO.  INVITRO shall indemnify
and hold MIRAGEN, its officers, directors, agents, and employees
harmless from any claims, demands, loss, damage, liability, or
expenses, including attorney's fees at trial, on appeal, and on any
petition for review, arising out of the wrongful acts or omissions of
INVITRO, its agents or employees.

     14.5.     INDEMNIFICATION BY MIRAGEN.  MIRAGEN shall indemnify
and hold INVITRO, its officers, directors, agents, and  employees
harmless from any claims, demands, loss, damage, liability, or
expenses, including attorney's fees at trial, on appeal, and on any
petition for review, arising out of the acts or omissions of MIRAGEN,
its agents or employees.

     In addition to its express product warranty and other obligations
under this Agreement, MIRAGEN agrees to indemnify and hold INVITRO
harmless from and against any and all costs and expenses incurred by
INVITRO hereunder in the event MIRAGEN fails to provide product
documentation in response to reasonable INVITRO requests for support
in applying for regulatory approval required in the Territory or in
INVITRO's required responses to other inquires as to the Guardian DNA
Products.

  12

     14.6.     FORCE MAJEURE.  Neither party shall be liable to the
other party for any loss, damage, detention, delay or failure of
performance, other than a failure timely to pay money (and provided
further, this paragraph shall not excuse INVITRO's failure to meet
minimum purchase obligations) resulting directly or indirectly from
any cause beyond its reasonable control, including without limitation,
declared or undeclared war, fire, flood, interruption of
transportation, embargo, accident, explosion, inability to procure or
shortage of supply of materials, equipment or production facilities,
prohibition of import or export, governmental orders, regulations, or
restrictions, rationing, strike, lockout or other labor troubles
interfering with production or transportation, or insurrection or
riots.

     14.7.     NOTICES.  Any notice or report shall be deemed given if
delivered personally or by confirmed facsimile transmission addressed
as follows, and in the case of facsimile transmission, to the
appropriate facsimile number shown below:

     To MIRAGEN:    MIRAGEN INC.
                    Attention:  Chief Financial Officer
                    10005 Muirlands, Suite O
                    Irvine, CA  92718
                    Facsimile No. (714) 454-1557

     To INVITRO:    INVITRO INTERNATIONAL
                    Attention: President
                    16632 Millikan Avenue
                    Irvine, California 92714
                    Facsimile No. (714) 851-4985 

or to such other address or facsimile number as from time to time may
be given in the manner permitted above.

     14.8.     GOVERNING LAW AND CHOICE OF FORUM.  This Agreement
shall be construed and governed in accordance with internal laws of
the State of California and the federal laws of the United States of
America.  The parties agree that the United Nations Convention on
Contracts for the International Sale of Goods shall not apply to this
Agreement.  In the event any legal action becomes necessary to enforce
or interpret the terms of this Agreement, the parties agree that such
action will be brought in the Orange County Superior Court, and the
parties hereby submit to the exclusive jurisdiction of said courts.

     14.9.     ARBITRATION.  The parties hereby submit all
controversies, claims and matters of difference arising as a result of
this Agreement or the transactions contemplated hereby to binding
arbitration conducted in accordance with the rules of the American
Arbitration Association ("AAA") and the arbitration shall take place
in Orange County, California. The arbitration shall be heard and
determined by three arbitrators. The award shall include interest from
the date of any breach or other violation to the date when the award
is paid in full at the prime rate of interest of Bank America in
effect from time to time. The parties agree that the award of the
arbitral tribunal will be the sole and

  13

exclusive remedy between them regarding any and all claims and
counterclaims presented to the tribunal.

     14.10.    CAPTIONS.  The captions and headings appearing in this
Agreement are inserted for convenience of reference only and shall not
affect the interpretation of this Agreement.

     14.11.    WAIVER OF CONFLICT OF INTEREST.  The parties
acknowledge that the first draft of this Agreement has been prepared
by corporate counsel who acts as counsel for both parties and who is a
director and stockholder of both parties.   Each party waives any and
all claims against each other or against such counsel as a result of
the inherent conflict of interest of such counsel hereby acknowledged.


     IN WITNESS WHEREOF, the parties have executed this Agreement as
of the date first above written.

                    MIRAGEN INC.


                    By: /s/ KEVIN B. MORTON            3-11-96
                        --------------------------------------

                    INVITRO INTERNATIONAL


                    By: /s/ W. RICHARD ULMER           3-11-96 
                        --------------------------------------