EXHIBIT 10.13

                               HELIX BIOCORE, INC.

                                 SELF-INSURANCE
                                 TRUST AGREEMENT

         This Agreement is made as of this 28th day of February, 1991, by and
between Helix BioCore, Inc. a Minnesota corporation ("HBI") and Richfield Bank &
Trust Co.
("Trustee").

         WHEREAS, HBI desires to indemnify its past and present directors and
officers, as listed on Exhibit A (the "Beneficiaries"), against liability claims
and expenses which they may become obligated to pay as a result of wrongful acts
or omissions or alleged wrongful acts or omissions arising out of duties which
they performed for HBI in their official capacity; and

         WHEREAS, as of the effective date of this Agreement, commercial
insurance coverage is prohibitively expensive and inadequate; and

         WHEREAS, qualified directors and officers would be unwilling to serve
in such capacities without adequate assurances of protection from such claims;
and

         WHEREAS, HBI desires to contribute to a trust fund assets sufficient to
pay all expenses incurred in investigating, settling and defending against such
claims and amounts due from such claims or to use such funds to purchase
insurance to provide protection against said claims and expenses arising
therefrom for the Beneficiaries; and

         WHEREAS, the Trustee is willing to receive and to hold such assets in
trust in accordance with the terms and conditions of this Agreement;

         THEREFORE, the parties agree as follows:

                                    ARTICLE I

                             ESTABLISHMENT OF TRUST

         1.1 Purpose of Trust. HBI hereby establishes this Trust for the
purposes of (a) indemnifying Beneficiaries in accordance with, and to the
fullest extent permissible under, the provisions of the Minnesota Business
Corporation Act, as it may from time to time be amended, and (b) paying officers
and directors liability insurance premiums, and hereby delivers to the Trustee
the sum of $200,000, to be held in a fund (the "Trust Fund") for the benefit of
the Beneficiaries in accordance with the terms of this Trust Agreement. HBI may
deliver additional funds to the Trustee from time to time to be similarly held.

         1.2 Initial Contribution. The Trustee acknowledges receipt of the
initial $200,000 contribution and agrees to hold, invest and reinvest such
assets as HBI may from time to time pay over, together with any income and
earnings thereon, in trust for the purposes stated herein in accordance with the
terms and conditions of this Agreement.

         1.3 Contract Rights. The rights of the Beneficiaries under this Trust
are contract rights based upon good and valuable consideration and shall be
enforceable the same as if the provisions hereof were set forth in a separate
written contract between HBI and each Beneficiary. It is expressly intended that
the indemnification provided hereunder shall extend to derivative actions
against officers or directors that otherwise qualify for indemnification
pursuant to the Minnesota Business Corporation Act.

                                    ARTICLE 2

                                     CONSENT

         2.1 Consent Defined. Wherever Consent is required in this Agreement,
Consent shall be defined as follows:

               (a)  HBI shall obtain a majority vote, approving the proposed
                    action, of each of two classes of Beneficiaries, namely,
                    current directors and officers of HBI (Class 1) and past
                    directors and officers of HBI (Class 2).

               (b)  The following Beneficiaries shall be excluded from such
                    classes and shall not be entitled to vote under this
                    Article:

                    (i) Heirs and personal representatives of deceased officers
                    and directors;

                    (ii) Mentally incompetent Beneficiaries;

                    (iii) Beneficiaries who cannot be located through the notice
                    procedures described in Section 8.7 and after additional
                    reasonable efforts;

                    (iv) Beneficiaries who do not respond to a notice requesting
                    Consent by the time designated in the notice; and

                    (v) If payment of a claim is involved, a Beneficiary on
                    whose behalf the claim would be paid.

               (c)  Class 2 shall not be entitled to vote on any Consent issues
                    until it contains at least 5 members, after the exclusions
                    in (b) above

         2.2 Notice. HBI, when seeking Consent as required in this Agreement,
shall notify all Beneficiaries eligible to vote, in accordance with Section 8.7,
providing said Beneficiaries with a reasonable time in which to respond. The
Beneficiaries shall respond with notice of approval or disapproval within the
time limits set out in the notice.

         2.3 Certificate of Consent. HBI shall promptly certify to the receipt
or non-receipt of such Consent upon written request of any party to this Trust
Agreement.

                                    ARTICLE 3

                                  BENEFICIARIES

         3.1 Date of Coverage. New directors and officers of HBI shall become
Beneficiaries under this Trust Agreement and shall be listed on Schedule A upon
election as a director or officer of HBI. Beneficiary status shall last for the
duration of the Trust Agreement unless a Beneficiary elects out, in accordance
with Section 3.3 below.

         3.2 Heirs and Representatives of Beneficiaries. The term Beneficiary
shall include heirs and representatives of deceased past directors and officers
against whom claims have been brought for wrongful acts or omissions arising out
of official duties performed for HBI.

         3.3 Election Out of Coverage. Any past or present officer or director
may elect to not become a Beneficiary under this Trust Agreement. Written notice
of election out of Beneficiary status shall be delivered to the Trustee and to
HBI and shall be effective upon receipt of such notice by the Trustee.

         3.4 Process of Indemnification. A Beneficiary seeking indemnification
under this Agreement shall submit to HBI a certificate containing the following
information:

               (a)  a description of the nature of the claim for which a right
                    to receive payments hereunder is asserted and the identity
                    of the persons who have made or threatened the claim;

               (b)  copies of all papers served on the Beneficiary in connection
                    with the claim;

               (c)  a written undertaking satisfactory to HBI to repay to the
                    Trust any amounts paid or applied to or for the use of the
                    Beneficiary pursuant to this Trust in the event a
                    determination is made by the Trustee that under applicable
                    law payments to the Beneficiary are not lawful and proper in
                    the circumstances; and

               (d)  a written undertaking satisfactory to HBI to keep HBI fully
                    informed of the progress of the claim and to deliver
                    promptly to HBI copies of all pleadings and other material
                    documents in relation to the proceeding.

         3.5 Certificate and Payment of Claim. A certificate delivered pursuant
to Section 3.4 shall be approved or disapproved in accordance with paragraph
5.1(c) and, if approved, paid in accordance with paragraphs 4.1(d), (e) and (f).

                                    ARTICLE 4

                          DUTIES AND POWERS OF TRUSTEE

         4.1 Trustee Duties.

               (a)  General Duty. To discharge the duties with respect to this
                    Trust solely in accordance with the terms and conditions of
                    this Trust Agreement for the purposes of indemnifying
                    Beneficiaries in accordance with the standards set out in
                    this Trust Agreement and paying directors and officers
                    liability insurance premiums.

               (b)  Establishment of Trust Fund. To establish a fund from which
                    to pay amounts described in (a). The Trustee shall deposit
                    in said fund all cash, cash equivalents such as certificates
                    of deposit and marketable government securities, and notes
                    contributed thereto by HBI.

               (c)  Investment. To invest and reinvest the trust funds only in
                    Authorized Investments. "Authorized Investments" shall
                    consist only of the following:

                    (i)  Obligations issued or guaranteed by the United States
                         Government, including obligations issued by its
                         agencies or by its instrumentalities;

                    (ii) Obligations (such as time deposits, Euro dollar time
                         deposits, letters of credit, certificates of deposit,
                         and bankers' acceptances) of commercial banks, savings
                         banks and savings and loan institutions participating
                         in the FDIC or FSLIC and organized under and regulated
                         by the United States Government and/or the State of
                         Minnesota, including the Trustee itself, and provided
                         that total principal and accrued income invested in any
                         such obligation shall at no time exceed the insured
                         limit of such obligation;

                    (iii) Money market funds whose funds are solely invested in
                         obligations described in paragraph (i) or (ii) above;

                    (iv) In exercising its investment authority with respect to
                         the Authorized Investments listed above, the Trustee
                         shall consider safety of principal, ready marketability
                         and interest yields (in that order) and may make
                         purchases and sales of investments through its own bond
                         department.

               (d)  Payment of Claims. To pay amounts from the Trust Fund,
                    consistent with the purposes stated in paragraph 1.1 as
                    follows: Upon receipt of a written notice of approval of a
                    claim by HBI or the arbitrator specified in Section 5.1(c)
                    of this Trust Agreement, the Trustee shall pay to the
                    Beneficiary from the Trust Fund the amount specified in the
                    written notice. In the event that the amount of cash held in
                    the Trust Fund is insufficient to make any payment required
                    pursuant to this Trust Agreement, the Trustee shall sell
                    investments in the Trust Fund so that the cash in the Trust
                    Fund is sufficient to make such payments.

               (e)  Notification of Insufficient Assets. If the Trustee is
                    instructed, in accordance with Section 4.1(d), to pay claims
                    and the assets in the Trust Fund are insufficient to pay all
                    of such claims, the Trustee shall immediately give written
                    notice to HBI and to the Beneficiary or Beneficiaries whose
                    claims are unpaid, of its inability to pay. HBI shall
                    respond to such notification in accordance with subparagraph
                    5.2(a).

               (f)  Priority of Claims. If the Trustee has two or more claims
                    and insufficient assets in the Trust Fund to satisfy all
                    claims, then the Trustee shall pay the claims according to
                    written instructions drafted by an authorized representative
                    of HBI, approved in accordance with the Consent procedures
                    described in Article 2. If no agreement is reached, the
                    priority of claims and division of funds in the Trust shall
                    be submitted to binding arbitration in accordance with the
                    Commercial Arbitration Rules of the American Arbitration
                    Association, as then in effect, with instructions for the
                    arbitrator to make a decision based on the following
                    factors. First, the arbitrator shall determine if any
                    Beneficiary has significantly greater culpability for the
                    underlying loss and, if so, such Beneficiary's claim shall
                    be the first to be reduced. If there still is insufficient
                    assets or there is a determination that no beneficiary had
                    significantly greater culpability, the reduction shall be
                    pro rata in accordance with each of the remaining
                    Beneficiary's loss. The decision of the arbitrator shall be
                    binding and conclusive on the parties and HBI shall pay the
                    costs of the arbitration, not including the costs of counsel
                    for the Beneficiaries.

               (g)  Payment of Insurance Premiums. Provided HBI obtains Consent,
                    the Trustee shall pay directors and officers liability
                    insurance premiums to a commercial insurer selected by HBI
                    in accordance with instructions from an authorized
                    representative of HBI.

               (h)  Recordkeeping. The Trustee shall keep accurate records of
                    the operation of the Trust, including instructions to the
                    Trustee from HBI as to payments to be made from the Trust,
                    which shall be available for inspection during regular
                    business hours at the principal office of the Trustee by
                    authorized representatives of HBI or by any Beneficiary. The
                    Trustee shall not be responsible for keeping records of
                    claims information submitted by Beneficiaries; such records
                    shall be maintained by HBI, as provided in Section 5.1(d).

               (i)  Accounting. No later than 60 days after the end of each
                    calendar year (which is the fiscal year of the Trust and of
                    HBI) and after the end of each quarter therein, to forward a
                    financial statement to HBI stating the balance in the Trust
                    Fund at the beginning and end of the period, current period
                    contributions, investments and reinvestments, activities of
                    the Trust, the amount and nature of all payments including
                    final payments and those for claims management, legal
                    expenses, claims paid and the like, together with the Trust
                    Fund balance. The first financial statement will be for that
                    portion of the calendar quarter year extending from the date
                    of establishment of the Trust to the following March 31st.
                    The Trustee shall make such statements available for review
                    by any Beneficiary listed on Schedule A or a legal
                    representative thereof, upon advance written notice to the
                    Trustee and during the Trustee's regular business hours.

         4.2 Trustee Powers.

               (a)  Exclusive Duties. The provisions of this Agreement set forth
                    exclusively the duties of the Trustee with respect to any
                    and all matters pertinent hereto and no implied duties or
                    obligations shall be read into this Trust Agreement against
                    the Trustee.

               (b)  Indemnity. The Trustee shall be indemnified and held
                    harmless by HBI against any and all costs, liabilities and
                    expenses (including expenses of litigation and counsel fees)
                    incurred by it with respect to payments made by reason of
                    any action or omission to act by the Trustee in good faith
                    under this Trust Agreement or otherwise incurred in good
                    faith by the Trustee, except such as arise from the
                    negligence or misconduct of the Trustee. The Trustee shall
                    be under no obligation to institute or defend any action,
                    suit or proceeding in connection with this Trust Agreement
                    unless first indemnified to its satisfaction. The Trustee
                    may consult counsel in respect of any question arising under
                    this Agreement and the Trustee shall not be liable for any
                    action taken or omitted in good faith upon advice of such
                    counsel.

               (c)  Reliance. The Trustee may conclusively rely upon and be
                    protected in acting upon any statement, certificate, notice,
                    request, consent, order or other document believed by it to
                    be genuine and to have been signed or presented by the
                    proper party or parties.

               (d)  To Employ Agents and Attorneys. The Trustee may select and
                    employ or retain such agents or attorneys as the Trustee
                    from time to time may deem necessary or advisable in
                    connection with the management and operation of the Trust
                    herein created, and pay the reasonable fees, commissions, or
                    salaries incurred on account thereof as an expense of
                    administration of the Trust.

               (e)  Compensation. The Trustee shall receive an annual
                    administrative fee of two hundred fifty dollars ($250) plus
                    seven-tenths of one percent (.7%) of the Trust assets,
                    valued as of December 31 of each year. Said fees shall be
                    paid by HBI or if HBI fails to so pay, said fee shall be
                    chargeable to, and constitute a direct charge against, the
                    Trust Fund. Fee schedules are subject to annual review and
                    adjustment, reasonably acceptable to both parties.

                                    ARTICLE 5

                            DUTIES AND POWERS OF HBI

         5.1 HBI Duties.

               (a)  Funding. HBI shall, contemporaneously with the execution of
                    this Agreement and in accordance with the Assignment
                    (Exhibit B), transfer to the Trustee $200,000 in cash, cash
                    equivalents or securities, as the initial funding of the
                    Trust. HBI in its discretion may make additional periodic
                    contributions of cash, cash equivalents or securities to the
                    Trust. Each such contribution shall be accompanied by an
                    Assignment (Exhibit B).

               (b)  Notification of Potential Claims. HBI shall notify the
                    Trustee of any potential claims by Beneficiaries as soon as
                    it is aware of such potential claims.

               (c)  Approval and Certification of Claims. The Board of Directors
                    of HBI shall appoint (1) a member or committee of said Board
                    (not including any director making a claim) or (2) special
                    independent legal counsel, to approve and certify claims of
                    certifying Beneficiaries pursuant to the provisions of this
                    Trust Agreement. Written notice of approval or denial of
                    each claim shall be given to the Beneficiary within 30 days
                    of receipt of the claim. If such appointed representative
                    rejects a claim as not within the indemnification provisions
                    of this Trust Agreement, the claimant may request in
                    writing, within 30 days of such denial, arbitration of the
                    claim as follows: The American Arbitration Association shall
                    be asked to appoint an arbitrator to rule on the matter in
                    accordance with its Commercial Arbitration Rules, as then in
                    effect. The decision of the Arbitrator shall be binding and
                    conclusive upon the parties and HBI shall pay the costs of
                    the arbitration, not including any costs of counsel for the
                    Beneficiary, unless the Beneficiary is successful in the
                    arbitration.

               (d)  Recordkeeping. HBI shall maintain records of all claims data
                    submitted by Beneficiaries for payment and shall make such
                    data available for inspection during regular business hours
                    by any Beneficiary.

               (e)  Authorized Representatives. HBI shall provide the Trustee
                    with a list of authorized representatives empowered to
                    instruct the Trustee as to all matters listed herein which
                    require instructions from an authorized representative of
                    HBI.

               (f)  Accounting. HBI shall provide the Trustee's year end
                    accounting statement to each Beneficiary and shall make all
                    accountings available for review by any Beneficiary or by
                    such Beneficiary's legal representative, upon advance
                    written notice to HBI and during HBI's regular business
                    hours.

         5.2 HBI Powers.

               (a)  Insufficient Assets. Upon receipt of Notification of
                    Insufficient Assets by the Trustee in accordance with
                    subparagraph 4.1(e), HBI shall have the option to:

                    (i)  Pay all or a portion of outstanding claims and
                         contribute a sum to the Trust Fund sufficient to enable
                         the Trust to continue in operation; or

                    (ii) Pay all or a portion of outstanding claims and
                    terminate the Trust according to the procedures set out in
                    paragraph 7.1(b); or

                    (iii) Seek payment from any insurer whose policy might cover
                    said claims; or

                    (iv) If it is unable to satisfy the claims under (i), (ii)
                    or (iii), not pay the claims and terminate the Trust in
                    accordance with paragraph 7.1(a).

               (b)  Insurance. Provided it has obtained Consent, HBI may direct
                    the Trustee to pay insurance premiums to a commercial
                    insurer for directors and officers liability insurance
                    premiums in accordance with subparagraph 4.1(g).

                                    ARTICLE 6

                        RESIGNATION OR REMOVAL OF TRUSTEE

         6.1 Resignation. The Trustee may resign from this Trust Agreement, and
thereby become discharged from the obligations hereby created other than its
duty to account, by notice in writing given to HBI no less than 60 days before
such resignation is to take effect, but such resignation shall take effect
immediately upon the substitution of a new trustee hereunder if such new trustee
shall be substituted before the time indicated by such notice and shall then
accept in writing the obligations thereof. If a successor trustee is not
appointed within said 60 days, the Trustee may petition any court of competent
jurisdiction to appoint a successor.

         6.2 Removal. HBI may at any time, with Consent, remove the Trustee by
giving written notice to the Trustee, to be effective upon the substitution of a
new trustee hereunder. Such substitution, as evidenced by the written acceptance
of the successor trustee, shall occur no later than 60 days from the date of
notice of removal.

         6.3 Successor Trustee Appointment. If, at any time hereafter the
Trustee shall resign, be removed, be dissolved or otherwise become incapable of
acting, or the bank or trust company acting as Trustee shall be taken over by
any governmental official, agency, department or board, the position of the
trustee shall thereupon become vacant. If the position of trustee shall become
vacant for any of the foregoing reasons or for any other reason, HBI shall
appoint a successor trustee to fill such vacancy, with Consent. Upon
substitution of the Trustee, a statement of accounts shall be rendered by the
Trustee to HBI.

         6.4 Obligations on Change of Trustee. Every successor trustee appointed
hereunder shall execute, acknowledge and deliver to its predecessor and to HBI
an instrument in writing accepting such appointment hereunder, and thereupon
such successor trustee, without any further act, shall become fully vested with
all the rights, immunities, and powers, and subject to all of the duties and
obligations, of its predecessor; but such predecessor shall, nevertheless, on
the written request of its successor, and upon payment of the expenses, charges
and other disbursements of such predecessor which are payable pursuant hereto,
execute and deliver an instrument transferring to such successor trustee all the
rights, immunities and powers of such predecessor hereunder; and every
predecessor trustee shall deliver all property and monies held by it hereunder
to its successor. Should any instrument in writing from HBI be required by any
successor for more fully and certainly vesting in such trustee the rights,
immunities and powers hereby vested or intended to be vested in the predecessor
trustee, any such instrument in writing shall and will, on request, be executed,
acknowledged and delivered by HBI.

                                    ARTICLE 7

                  EXTENSION, AMENDMENT AND TERMINATION OF TRUST

         7.1 Extension, Amendment and Termination. Except as set forth in
subparagraphs (a), (b) and (c) below, this Trust Agreement shall be irrevocable,
including, without limitation, by HBI.

         (a)      Extension. The Trust term may be extended by HBI with Consent,
                  provided, however, that the Trust term shall not be extended
                  beyond 21 years after the death of the last surviving director
                  or officer serving as of the date of this Agreement.

         (b)      Amendment. The Trust Agreement may be amended by HBI, with the
                  consent of two-thirds of each class of Beneficiaries described
                  in paragraph 2.1(a), if needed at any time to bring it into
                  compliance with any applicable statutory or case law or
                  governmental regulations.

         (c)      Termination. This Trust Agreement may be terminated in
                  accordance with the provisions of this subparagraph.

                  (i)    The Trust may be terminated at any time for the
                         following reasons:

                        (A)     HBI is dissolved or liquidated as a corporate
                                entity; or

                        (B)     Less than $50,000 in funds remains in the Trust
                                and HBI does not intend to further fund the
                                Trust; or

                        (C)     There is a Change in Control of HBI defined as
                                follows:

                              (1)    For purposes of this Article, "Change in
                                     Control" shall mean a change in control
                                     which would be required to be reported in
                                     response to item 5(f) on Schedule 14A of
                                     Regulation 14A promulgated under the
                                     Securities Exchange Act of 1934, as amended
                                     (the "Exchange Act"), whether or not HBI is
                                     then subject to such reporting requirement,
                                     including, without limitation, if:

                                    (I)      Any "person" (as such term is used
                                             in Sections 13(d) and 14(d) of the
                                             Exchange Act) becomes a "beneficial
                                             owner" (as defined in Rule 13d-3
                                             under the Exchange Act), directly
                                             or indirectly, of securities of HBI
                                             representing 30% or more of the
                                             combined voting power of HBI's then
                                             outstanding securities; or

                                    (II)     There ceases to be a majority of
                                             the Board of Directors comprised of
                                             individuals described in (III)
                                             below.

                                    (III)    For purposes of this subsection
                                             (1), "Board of Directors" shall
                                             mean: (A) individuals who on the
                                             effective date hereof constituted
                                             the Board of HBI; and (B) any new
                                             director who subsequently was
                                             elected or nominated for election
                                             by a majority of the directors who
                                             held such office immediately prior
                                             to a Change in Control.

                             (2)    Change in Control shall also mean the
                                    commencement of any insolvency proceeding by
                                    or against HBI including the appointment of
                                    a receiver.

                (ii)    The Trust may be terminated for a reason listed in (i)
                        in accordance with the following rules:

                         (A)    If the Trust Fund contains less than $50,000 in
                                assets or if HBI is able to obtain liability
                                insurance for directors and officers covering
                                all acts up to the date of termination for six
                                years following termination, HBI may terminate
                                the Trust, provided it has obtained Consent. HBI
                                shall give 60 days advance written notice of
                                termination to the Trustee and to all
                                Beneficiaries.

                         (B)    If Trust Fund assets total $50,000 or more, the
                                Trust shall go into frozen status for six years.
                                HBI shall give 60 days advance written notice of
                                frozen status to the Trustee and to all
                                Beneficiaries. Frozen status shall mean that no
                                new Beneficiaries will be added to Exhibit A.
                                During the six-year frozen status period, the
                                Trustee will pay duly certified claims which are
                                based upon acts or omissions occurring both
                                prior and subsequent to the date of notice of
                                frozen status. At such time as the Trust Fund is
                                depleted of all assets, the Trust shall
                                terminate, even if prior to the expiration of
                                the six-year period.

                (iii)   If this Trust Agreement has not terminated in accordance
                        with (i) and (ii) above by December 31, 2000, or if the
                        Trust term has not been extended in accordance with
                        paragraph 7.1(a), then the following rules shall apply:

                        (A)     If the Trust Fund contains less than $50,000 in
                                assets as of December 31, 2000 or HBI obtains
                                Consent, then HBI may terminate the Trust as of
                                December 31, 2000, upon 60 days advance written
                                notice to all Beneficiaries and to the Trustee.

                        (B)     If Trust Fund assets total $50,000 or more as of
                                December 31, 2000, the Trust shall go into
                                frozen status for six years as described in
                                subsection (ii) (B) above.

                (iv)    Upon termination of this Trust Agreement, any assets
                        remaining in the Trust Fund shall be distributed in the
                        following order of priority:

                        (A)     To HBI; or

                        (B)     If HBI is in voluntary or involuntary bankruptcy
                                as of that date, to the trustee in bankruptcy;
                                or

                        (C)     If HBI shall have ceased to exist, then to the
                                successor thereto, or, if more than one
                                successor, then pro rata among such successors;
                                or

                        (D)     If there is no successor thereto, then to the
                                HBI shareholders of record as of the date of
                                notice of termination or notice of frozen
                                status, whichever is applicable.

                        (E)     If there are no shareholders, then to the State
                                of Minnesota.

                                    ARTICLE 8

                                  MISCELLANEOUS

         8.1 Spendthrift Provision. The Trust principal and income shall not be
applied (a) to discharge the debts of HBI under any circumstances except as
specifically provided in this Trust Agreement to satisfy HBI's obligation to
indemnify its officers and directors, or (b) to discharge the debts of any
Beneficiary, except as specifically provided in this Agreement. No Beneficiary
shall have any power to sell, assign, transfer, encumber or in any other manner
to anticipate or dispose of his or her interest in the Trust, or the income
produced thereby, before distribution by the Trustee to said Beneficiary. Any
distribution from the Trustee to a Beneficiary shall be used to satisfy the
claims of creditors specified in the corresponding certificate submitted to the
Trustee by the Beneficiary. HBI shall have no power to sell, assign, transfer,
encumber or otherwise dispose of any Trust principal or interest, and no
creditor of HBI shall have any right to or claim against Trust income or
principal.

         8.2 Binding Effect. This Trust shall be binding upon and inure to the
benefit of the heirs, personal representatives, successors and assigns of all
parties hereto.

         8.3 Representations. No representations or warranties have been made by
or shall be implied against or as to any party with respect to the facts or
transactions upon which this Trust Agreement is based. The Trustee is and shall
be independent.

         8.4 Partial Invalidity. The invalidity or unenforceability of any
provision of this Trust Agreement shall not affect the validity or
enforceability of any other provision of this Trust Agreement, which shall
remain in full force and effect.

         8.5 Construction. Nothing in this Trust Agreement shall be construed to
eliminate or modify the indemnification requirements of Minnesota law.

         8.6 Complete Agreement. This Trust Agreement constitutes the entire
understanding between the parties hereto with respect to the subject matter
hereof, and no agreements or representations, verbal or otherwise, express or
implied, other than those set forth expressly in this Trust Agreement have been
made by any party hereto with respect to the subject matter hereof.

         8.7 Notice. All certificates, notices, requests for Consent and
otherwise, demands, instructions to the Trustee and other communications
hereunder shall be in writing and shall be deemed to have been duly given if
addressed and delivered or deposited in the United States mails by certified
mail, return receipt requested, postage prepaid, to the parties as follows:

                           Helix BioCore, Inc.
                           3905 Annapolis Lane
                           Plymouth, Minnesota 55447
                           Attention: Chief Executive Officer

                           Richfield Bank & Trust Co.
                           6625 Lyndale Avenue South
                           Richfield, Minnesota 55423
                           Attention: Trust Department

         8.8 Governing Law. This Trust Agreement shall be governed by, and
construed in accordance with, the laws of the State of Minnesota.

         8.9 Execution. This Trust Agreement is executed in multiple copies,
each copy being an original counterpart and shall be deemed one and the same
instrument.

         IN WITNESS WHEREOF, the Trustee and HBI have caused this Trust
Agreement to be signed as of the date and year first above written.

                                       HELIX BIOCORE, INC.


                                       By: /S/ M.A. Villafana

                                       Its: Chairman and CEO

                                       RICHFIELD BANK & TRUST CO.


                                       By: /S/ Daniel E. Caswell

                                       Its: Trust Officer





                                                                       EXHIBIT A

NAMES AND ADDRESSES OF PAST AND PRESENT DIRECTORS AND OFFICERS

Manuel A. Villafana                        James F, Lyons
1482 Hunter Drive                          1179 West Burke Avenue
Medina, MN 55391                           Roseville, MN 55113

Richard W. Kramp
1285 Karth Lake Circle
Arden Hills, MN 55112

Charles F. Cuddihy, Jr.
16993 Chilton Hill Road
Minnetonka, MN 55345

John S. Salstrom
1250 W. Minnehaha Parkway
Minneapolis, MN 55419

John R. Holroyd
6905 Limerick Lane S.
Edina, MN 55435

Niguel O. Villarejos
1749 N. Farm Road
Long Lake, MN 55356

John H. Junghauer
12122 Everton Avenue N.
White Bear Lake, MN 55110

Howard C. Root
4128 Beard Avenue South
Minneapolis, MN 55410

Thierry Hermann
Fournitures Hospitalieres
Z.A. de Mulhouse-Heimabrunn
B.P. 9
68990 Heimsbrunn
FRANCE

David L. Boehnen
71 Otis Lane
St. Paul, MN 55104

Frank H. Voigt
5036 Belmont Avenue South
Minneapolis, MN 55419

Joel D. Hixson
225 Forest View Lane
Plymouth, MN 55441




                                                                       EXHIBIT B

                                   ASSIGNMENT

         Helix BioCore, Inc., a Minnesota corporation ("HBI") hereby transfers
to Richfield Bank & Trust Co. (the "Trustee") the sum of Two Hundred Thousand
Dollars ($200,000) to be held by the Trustee pursuant to the Helix BioCore, Inc.
Self-Insurance Trust Agreement dated February 28, 1991 (the "Trust Agreement").
The Trustee undertakes to hold and invest the funds transferred hereby in
accordance with the terms of the Trust Agreement and to keep such funds separate
and free from any claim, interests or judgments of the Trustee or any person
claiming an interest through the Trustee.

Dated:     March 18, 1991               HELIX BIOCORE, INC.


                                        By: /S/ Howard C Root

                                        Its: Secretary and General Counsel


                                        RICHFIELD BANK & TRUST CO.


                                        By: /S/ Daniel E. Caswell

                                        Its: Trust Ofiicer