Document:

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                                                                   EXHIBIT 10.19

                                      LEASE

       THIS LEASE is made and entered into this 10th day of April, 2000, by and
between Prairie Warehousing LLP (hereinafter called "Landlord") and Third Wave
Technologies, Inc., a Wisconsin corporation, (hereinafter called "Tenant").

                                   WITNESSETH

       1. PREMISES TERM: Landlord leases to Tenant and Tenant hires from
Landlord approximately 36,000 square feet (hereinafter called the "Premises")
known as 220 Business Park Drive, Sun Prairie, Wisconsin (hereinafter called the
"Building") as depicted on the drawing attached hereto as Exhibit A and
incorporated herein by reference, for a term (the "Term") of thirty seven (37)
months commencing on or about the 1st day of May, 2000, and ending on the 31st
day of May, 2003, unless sooner terminated as hereinafter provided.

       2. OPTION TO RENEW: Provided Tenant is not in default hereof beyond
applicable notice and cure periods, Tenant shall have two (2) options, by
written notice received by Landlord at least six (6) months prior to the
expiration of the then existing Term, to renew this Lease each for a term of
three (3) years (each a "Renewal Term"). Each Renewal Term shall be upon the
same terms and conditions as the initial Term except the monthly Rent shall
continue to be adjusted as provided in paragraph 4.

       3. USE OF PREMISES: The Premises shall be used solely for office,
laboratory, light manufacturing, warehouse and distribution purposes all in
accordance with this Lease. Tenant shall not use or occupy, or permit the use of
occupancy of, the Premises, or any part thereof, in any unlawful manner or for
any illegal purpose or in such manner as to constitute a nuisance or violate the
terms and conditions of any certificate of occupancy applicable to the Premises,
or for any purpose or in a manner liable to cause structural injury to the
Building, and shall not use or occupy or permit the use or occupancy of the
Premises, for other than purposes of the nature and to the extent permitted by
the laws, rules, regulations and ordinances of the applicable governmental
authorities.

       4. RENT: During the initial Term and the Renewal Terms, if exercised,
Tenant hereby covenants and agrees to pay rent (the "Rent"), in advance, each
month beginning on the first day of the first calendar month after the
commencement of this Lease. Rent for the first thirteen (13) months of the
initial Term shall be the sum of $18,000.00 per month and each year thereafter,
beginning on June 1st of each calendar year thereafter,

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the amount due per month shall change to equal the amount due for the month
immediately prior to such change times [one plus the percentage increase in the
CPI-U over the twelve (12) months beginning fifteen months prior to the change
and ending three months prior to the change] CPI-U shall be defined as the
Bureau of Labor Statistics U.S. City Average, All Items Consumer Price Index For
all Urban Consumers (1982/1984 Base). Rent for any period which is for less than
one (1) month shall be a prorated portion of the monthly installment herein
based upon a thirty (30) day month. Rent shall be paid to Landlord, without
deduction or offset, in lawful money of the United States of America and at such
place as Landlord may from time to time designate in writing.

       5. RENT ADJUSTMENT: Rent shall be adjusted each year by "Tenant's Share"
of the net aggregate amount of Taxes, Insurance and Operating Expenses for that
year (as such terms are defined below). Tenant's Share is agreed upon as being
42%. Prior to the commencement of the Lease, Landlord shall estimate the
Tenant's Share of Taxes, Insurance and Operating Expenses for the lease year
(based upon historic usage and arms length service contracts) and that amount
shall be added to the Rent to equal the "Adjusted Annual Rent" for the current
year. All monthly installments of Rent shall be adjusted to the extent necessary
to pay Adjusted Annual Rent in equal monthly installments. At the end of each
lease year, Landlord shall calculate the actual cost of Taxes, Insurance and
Operating Expenses and supply Tenant, within thirty (30) days of the end of such
lease year, with a detailed analysis thereof, together with a statement showing
any under or overpayment by Tenant due to the prior year's estimate. Any over or
under payment shall be settled between the parties by lump sum payment within
sixty (60) days of the end of each lease year. At the end of each lease year,
the Adjusted Annual Rent shall be adjusted to reflect the previous year's costs
(and reasonable estimates for the next year) and such amount shall be added to
the Rent in equal monthly installments for the next lease year. Landlord shall
keep and make available to Tenant for a period of ninety (90) days after each
lease year, records in reasonable detail of Taxes, Insurance and Operating
Expenses for each lease year and shall permit Tenant and the representatives of
Tenant to examine such statements at any reasonable time during business hours.
If Tenant shall dispute any item included by Landlord in determining Taxes,
Insurance or Operating Expenses and such dispute is not amicably settled between
Landlord and Tenant within sixty (60) days after any statement for Adjusted
Annual Rent has been rendered, either may, during the twenty (20) days next
following the expiration of said sixty (60) day period, notify the other of its
election to arbitrate said dispute and may then refer such disputed item or
items to one of the Big Five accounting firms selected by Landlord for decision
and the decision of such firm shall be conclusive and binding upon Landlord

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and Tenant. The expense involved in such determination shall be borne by the
party against whom a decision is rendered by said accountants, provided that if
more than one item is disputed and the decision shall be against each party in
respect to any item or number of items so disputed, then the expenses shall be
apportioned according to the dollar amount of the items decided against each
party. Pending a decision, Tenant shall pay on the basis of Adjusted Annual Rent
subject to a proper adjustment upon rendition of the decision. If Tenant shall
not dispute any item or items of any such statement within sixty (60) days after
such statement has been rendered, Tenant shall be deemed to have approved such
statement.

       6. TAXES: "Taxes" shall mean all taxes and assessments accruing during
the term of the Lease, special or otherwise and sewer charges, if any, including
expenses incurred in connection with disputing or contesting the amount thereof
levied, or assessed for the year in question, or a partial year, upon or with
respect to the Building and the land upon which it is located, by Federal, State
or local government. Should any governmental authority having jurisdiction
impose a tax and/or assessment (other than an income or franchise tax) upon or
against the Rent payable hereunder or on the privilege or renting, leasing, or
letting real property, either by way of substitution for the taxes and
assessment levied or assessed against such land and such buildings, or in
addition thereto, such tax and/or assessments shall be deemed to constitute a
tax and/or assessment against such land and improvement for the purposes of this
paragraph.

       7. LANDLORD SERVICES-OPERATING EXPENSES: Landlord shall provide Tenant
and Tenant shall pay Tenant's Share of "Operating Expenses" for the following
services:

       (a) Individually controlled heat and air conditioning necessary to
maintain the Premises at comfortable temperatures on such working days and hours
as are reasonably consistent with Tenant's intended use and occupancy; provide,
however, if separately metered and controlled, the cost of the utility services
powering the said heat and air conditioning equipment shall be billed directly
to the Tenant; otherwise it shall be billed on a prorata basis, unless special
usage by any Tenant in the Building is a factor;

       (b) Snow removal service for the parking lots, footways and driveway
appurtenant to the Building and for all approaches thereto;

       (c) Regular maintenance (including bi-annual sealing and spot patching,
but not resurfacing) of all parking areas, footway and driveway appurtenant to
the Building;

       (d) During business hours, including evenings, reasonable illumination
for all parking areas and footways appurtenant to the Building; and

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       (e) Gardening and landscaping of the property upon which the Building is
located.

       The foregoing services shall be the only costs included in "Operating
Expenses" and, without limitation, no charges for management or property
supervision shall be included in Operating Expenses charged to the Tenant.

       8. LANDLORD SERVICES - NON-OPERATING EXPENSES: Landlord shall at
Landlord's sole cost and expense, not to be included in Operating Expenses, (i)
maintain and replace, when necessary, all structural components of the Building,
including, without limitation, the roof; (ii) replace, when necessary, all the
HVAC units servicing the Building, and the plumbing, electrical, fire protection
and utility systems servicing the Building and (iii) resurface, when necessary,
the parking lots, footways and driveways appurtenant to the Building. Landlord,
while not warranting that any of the Building services stipulated in Paragraph 7
or 8 shall be free from interruptions or suspensions caused by repairs,
renewals, improvements, alterations, strikes, lockouts, accidents, inability of
Landlord to procure such service, or to obtain fuel or supplies or for other
cause or causes beyond Landlord's reasonable controls, shall nevertheless
diligently attempt to make such repairs or renewals to Building distribution
lines and facilities as may be required to restore any such service so
interrupted or suspended. An interruption or suspension of, or fluctuation in,
any Building service (resulting from any of said cause or causes) shall never be
deemed a constructive eviction or evictions or disturbance of Tenant's use and
possession of said Premises, or any part thereof nor render Landlord liable to
Tenant for damages, nor relieve Tenant from performance of Tenant's covenants
and agreements hereunder. Landlord shall not be required to repair, replace or
maintain any of Tenant's construction or leasehold improvements.

       9. USE AND REPAIR OF PREMISES BY TENANT; UTILITIES: Throughout the Term
and Renewal Term of this Lease, tenant will, at its cost, keep and maintain the
interior of the Premises, including regular maintenance of the HVAC units and
the plumbing, electrical, fire protection and utility systems and all of
Tenant's construction and leasehold improvements in a good state of repair,
ordinary wear and tear and damage by the elements or by acts of God only
excepted. In addition, Tenant shall be liable for replacement of all components
of the Building which are damages through the negligence of Tenant, its agents,
guests and/or invitees. Tenant further agrees to deliver up and surrender to
Landlord possession of the Premises upon the expiration of this Lease in as good
a condition as when taken, ordinary wear and tear and damage from the above
specified causes excepted. Tenant shall be solely responsible for and promptly
pay all

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charges for heat, gas, electricity or any other utility separately metered and
used or consumed in the Premises and billed directly to the Tenant by the
utility company involved.

       10. PARKING, COMMON AREAS AND FACILITIES: Landlord shall provide to
Tenant the use of the parking lots, footways and driveways appurtenant to the
Building (including any lots, driveways or footways which may in the future be
constructed on the adjacent lot) for the use, in common, with the other tenants
of the Building, and their employees and invitees; provided, however, that the
fifty (50) spaces designated on Exhibit A shall be set aside for, marked and
designated for use solely by Tenant. Beginning November 1, 2000, Tenant shall
have the exclusive use of one hundred twenty (120) reserved and marked parking
spaces. All automobile parking areas, driveways, entrances and exits thereto,
and other facilities furnished by Landlord in or near the Building, including,
the truck ways, loading docks, pedestrian sidewalks and ramps, landscaped areas,
and other areas and improvements provided by Landlord for the exclusive use, in
common, of tenants, their officers, agents, employees and customers, shall at
all times be subject to the exclusive control and management of Landlord and
Landlord shall have the right from time to time to establish, modify and enforce
reasonable rules and regulations with respect to all facilities and areas
mentioned in this Paragraph. The Landlord shall have the right to construct,
maintain and operate lighting facilities on all said areas and improvements, to
police the same and to do and perform such other acts in and to said areas and
improvements as, in the use of good business judgment, Landlord shall determine
to be advisable with a view to the improvement of the convenience and use
thereof by Tenant, other tenants and their officers, agents, employees and
customers.

       11. RIGHTS RESERVED BY LANDLORD: In addition to all remedies which are
allowed to Landlord by law and equity and without limitation on any of them,
Landlord reserves the following rights:

       (a) To enter said Premises at all reasonable times (1) for the making of
such inspections, repairs, alterations, improvements or additions, of, or to,
said Premises or Building as Landlord may deem necessary or desirable; (2) to
exhibit said Premises to others during the last six (6) months of the Term or
renewal term hereunder; and (3) for any purpose whatsoever, related to the
safety, protection, preservations or improvement of said Premises or of the
Building or of Landlord's interest. The rights granted to Landlord pursuant to
this Paragraph, shall not require Landlord to make any repairs to the Premises
other than those herein specifically agreed to be made by Landlord nor otherwise
extend any of Landlord's other obligations;

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       (b) At any time or times Landlord, either voluntarily or pursuant to
governmental requirements, may at Landlord's expense, make repairs, alterations
or improvements in or to the Building or any part thereof, and during such times
may temporarily close entrances, doors, corridors, elevators or other public
facilities;

       (c) To charge Tenant any expense (including overtime or premium costs
incurred by Landlord) resulting from repairs, alterations, decorating or other
work performed in said Premises or the Building at Tenant's request made at
other than business hours;

       (d) From and after the commencement date of this Lease and throughout the
Term or renewal term of this Lease to require Tenant to protect, indemnify and
save harmless Landlord from and against any and all liability to third parties
incurred by any act or neglect of Tenant, or any of its agents, servants or
employees, in, on or about the Premises; and Tenant at all times shall at its
own cost protect Landlord with public, liability insurance and property damage
insurance in a responsible insurance company or companies authorized to do
business in the State of Wisconsin, in the amount no less than $1,000,000.00 for
injury to one person and no less than $1,000,000.00 for injury for two or more
persons and $500,000.00 for damages to property. Landlord shall be named as an
additional insured under said policy for the Premises. Tenant shall within ten
(10) days of the commencement date of this Lease, or as soon thereafter as made
available by the insurance company, deposit with Landlord a copy of all such
policies or certificates showing such insurance to be then in force; and

       (e) Require Tenant, at its own expense but subject to its right to
contest the validity thereof, to promptly comply with the requirements of every
applicable statute, law, ordinance, fire regulation, and with every applicable
lawful regulation and order, with respect to the condition and maintenance of
the Premises to the extent that Tenant is obligated to repair and maintain the
same and with respect to Tenant's use or occupation of the Premises.

       Landlord may exercise all or any of the foregoing rights hereby reserved
without being deemed guilty of an eviction or a constructive eviction or
disturbance of Tenant's use and possession, without being liable in any manner
to Tenant, and without elimination or abatement of Rent, or payment of other
compensation, and such acts shall in no way affect this Lease.

       12. MUTUAL WAIVER OF SUBROGATION: Notwithstanding anything to the
contrary in the Lease, Landlord and Tenant hereby release each other to the
extent of their respective insurance coverage, from any and all liability to the
other or anyone claiming through or under it by way of subrogation or otherwise,
for any loss or damage to property covered by the fire or extended coverage
insurance policies carried or required to be

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carried by Landlord and Tenant, respectively, even if such damage shall have
been caused by the fault or negligence of the other party, or anyone claiming
through or under it, provided however, that this release shall be applicable and
in force and effect only with respect to loss or damage occurring during such
time as such policies shall contain a clause or endorsement to the effect that
any such release shall not adversely affect nor impair such policies or
prejudice the right to recovery thereunder. Each party agrees that its policies
of insurance will include such a clause or endorsement so long as the same shall
be obtainable.

       13. INSURANCE: Landlord shall provide during the Term and Renewal Term,
if exercised, and Tenant shall pay for Tenant's Share of "Insurance" herein
defined as property damage, fire, extended coverage, vandalism, malicious
mischief and all-risk insurance on the Building and the improvements located on
the land upon which the Building is situated in an amount not less than the full
replacement value of the Building and such improvements and with a deductible
not in excess of $1,000.00. Such insurance to be maintained with carriers
selected by Landlord and approved by Tenant in its reasonable discretion, and to
include Landlord and Tenant as insureds thereunder. At Tenant's request,
Landlord shall provide to Tenant certificates of such insurance which shall
provide that the insurer shall provide notice to Tenant prior to the
cancellation of any coverage under the subject policy.

       14. LOSS OR DAMAGE TO PROPERTY:

       (a) All personal property belonging to Tenant or to any other person
located in or about said Premises or the Building shall be there at the sole
risk of Tenant or such other person, and neither Landlord nor Landlord's agents
or employees shall be liable for the theft or misappropriation thereof, nor for
any damages or injury thereto, nor for death or injury of Tenant or any other
persons or damage to property caused by but not limited to the following: water,
snow, frost, steam, heat, cold, dampness, failing plaster, explosions, sewers or
sewage, gas, odors, noise, the bursting or leaking of pipes, plumbing,
electrical wiring and equipment and fixtures of all kinds or by any act or
neglect of other tenants or occupants of the Building, or of any other person,
or caused in any other manner whatsoever. Tenant shall protect, indemnify and
save harmless, Landlord from all losses, costs, including attorneys fees, or
damages sustained by reason of any act or other occurrence or failure to act
causing death or injury to any person or damage to property whosoever or
whatsoever due directly or indirectly to the use or occupancy of said Premises
or any part thereof by Tenant, or due directly or indirectly to any breach or
default

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on the part of Tenant in the performance of any covenant or agreement, on the
part of Tenant to be performed.

       (b) Tenant covenants, upon notice from Landlord, to resist and defend, at
Tenant's expense, such action or proceeding by counsel reasonably satisfactory
to Landlord.

       (c) Landlord shall not be liable to anyone for cessation of any of the
services that Landlord is required to provide under this Lease, including but
not limited to, public utility services and air conditioning, due to inability
to obtain fuel, electricity, service or supplies from the sources from which
they are usually obtained, due to failures in the equipment used to provide such
services, or for any other reason beyond the control of the Landlord. Any such
interruption of any of the above services shall never be deemed an eviction or
disturbance of the Tenant's use of the Premises or any part thereof, or render
Landlord liable to Tenant for damages, or relieve Tenant from performance of
Tenant's obligations under this Lease. Landlord, however, shall promptly take
the necessary steps to terminate such interruptions as expeditiously as possible
under the circumstances.

       15. HOLDOVER: Should Tenant withhold from Landlord possession of the
Premises after the expiration or termination of this Lease, whether by lapse of
time or otherwise, then in that event Landlord may elect, by written notice to
Tenant, to constitute such withholding of the Premises as a holdover under and
renewal of this Lease, otherwise such withholding shall constitute only a
month-to-month tenancy at a monthly rental rate not less than the last monthly
installment of Rent adjusted to indicate a 10% increase, in addition to Adjusted
Rent or additional rent, if any, payable hereunder.

       16. ASSIGNMENT AND SUBLETTING: Tenant shall not either voluntarily, or by
operation of law, assign, or transfer this Lease or, any interest therein, and
shall not sublet the said Premises or any part thereof, or any right or
privilege appurtenant thereto, or allow any other person (employees, agents,
servants, and invitees of Tenant excepted) to occupy or use the said Premises,
or any portion thereof, without first obtaining the written consent of Landlord,
which consent may not be unreasonably withheld. Consent to one assignment or
sublease shall not constitute a waiver of this provision, and all later
assignments and subleases shall likewise be made only upon prior written consent
of Landlord. Assumption agreements shall be in a form reasonably acceptable to
Landlord. In the event of any assignment or subletting, Tenant shall
nevertheless at all times remain fully responsible and liable for the payment of
the rent herein specified and for compliance with all Tenant's other obligations
under the terms, provisions and covenants of this Lease. Upon the occurrence of
a default beyond applicable notice and cure periods as hereinafter

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provided, if the demised premises or any portion thereof are then assigned or
sublet, Landlord, in addition to any other remedies herein provided or provided
by law, may at its option collect directly from such assignee or subtenant all
rents becoming due to Tenant under such assignment or sublease and apply such
rent against any sums due to it by Tenant hereunder; and no such collection
shall be construed to constitute a novation or a release of Tenant from the
further performance of its obligations hereunder. Consent to any such assignment
or subletting shall in no way relieve Tenant of any liability under this Lease.
Any such assignment or subletting without such consent shall be void, and shall,
at the option of Landlord, constitute a default under the terms of this Lease.

       Landlord reserves the right to assign its interest under this Lease. Upon
receipt of notice of any assignment by Landlord, Tenant shall fulfill each and
every obligation and make all payments required under this Lease to such
assignee, and Tenant further agrees that upon receipt of notice of any
assignment by Landlord, Tenant will execute any acknowledgment, consent or
attornment agreement that said assignee may require.

       This Lease and the covenants and conditions herein contained shall inure
to the benefit and be binding upon Landlord, its successors and assigns, and
shall be binding upon Tenant, its successors and assigns, and shall inure to the
benefit of Tenant and only such assignees of Tenant to whom an assignment by
Tenant has been consented to in writing by Landlord.

       17. ALTERATIONS: Tenant shall make no alterations in, or additions or
improvements to, said Premises without the written consent of Landlord first had
and obtained which consent will not be unreasonably withheld; provided, however,
that nonstructural alterations costing, on a per project basis, less than
$20,000.00 shall not require Landlord's consent. Any addition, alterations or
improvements made by Tenant shall be made in a good and workmanlike manner and
shall become and remain a part of the Premises, and be and remain the property
of Landlord upon the termination of this Lease or Tenant's occupancy of the
Premises; notwithstanding the above, Landlord may, by giving written notice to
the Tenant, require Tenant to restore the Premises to the same condition they
were in at the commencement of this Lease. Tenant shall indemnify and save
harmless Landlord from and against all expenses, liens, claims or damages to
either property or person which may or might arise by reason of such repairs,
alterations, improvements or additions.

       18. UNTENANTABILITY: In the event the Premises, or any part thereof,
shall be destroyed or damaged, and such destruction or damage may be reasonably
repaired within one hundred twenty (120) days from the happening of such
destruction or damage, Tenant

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shall not be entitled to surrender possession of the Premises, or any part
thereof, nor shall Tenant's liability to pay Rent under this Lease cease, but in
case of any such destruction or damage, Landlord shall repair the same with all
reasonable speed and shall complete such repairs within one hundred twenty (120)
days from the happening of such destruction or damage, subject to delays beyond
Landlord's reasonable control. If Tenant shall thereby be deprived of the
occupancy of any part of the Premises, a proportionate allowance shall be made
to Tenant from the Rent, corresponding to the time during which and to the part
of the Premises of which Tenant shall so be deprived on account of such
destruction or injury of or the making of such repairs; however, this does not
apply to interruption or deprivation of use of any of the common areas as
defined in Paragraph 11 herein. In the event that any destruction or damage
cannot reasonably be repaired within one hundred twenty (120) days from the
happening of such destruction or damage, either Landlord or Tenant shall have
the right to terminate this Lease by giving written notice within thirty (30)
days from the happening of such destruction or damage.

       19. REMEDIES OF LANDLORD: All rights and remedies of Landlord herein set
forth are in addition to any and all rights and remedies allowed by law or
equity.

       (a) This Lease is made upon the condition that Tenant shall punctually
perform all of its covenants and agreements as herein set forth and if:

              1) Tenant defaults in payment of Rent, Adjusted Rent or additional
rent, or any additional charge or amount of money, to be paid by Tenant as
provided in this Lease and such default shall continue uncorrected for a period
of five (5) days after written notice to the Tenant thereof, then Tenant shall
pay to Landlord a late charge equal to 10% of the amount past due in addition to
all past due amounts owed, plus any attorneys fees or other costs incurred by
Landlord by reason of Tenant's failure to pay rent and/or other charges when due
hereunder. Acceptance of such late charges represent a fair and reasonable
estimate and in no event constitute a waiver of Tenant's default with respect to
such overdue amount, nor prevent Landlord from exercising any of the rights and
remedies granted hereunder, including but not limited to, any such acceleration
of all amounts due for the term of this Lease or exercised option period.

              2) Tenant default in the prompt and full performance and
observance of any of the terms and conditions of this Lease to be performed or
observed by Tenant and not relating to the payment of money, and any such
default shall continue uncorrected for a period of thirty (30) days after
written notice to the Tenant thereof, or if any such last mentioned default
cannot be reasonably corrected within such thirty (30) day period, then if
Tenant shall not within such period have commenced in good faith to correct such
default.

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              3) Tenant abandons the Premises.

              4) Any execution, attachment or other order of court shall be
issued upon or against the interest of Tenant in this Lease and shall continue
for a period of thirty (30) days after notice, then in any such event, in
addition or any, and all rights and remedies allowed by law and equity, Landlord
may, with or without further notice, forthwith, terminate this Lease and
Tenant's right to possession of the Premises, or Landlord may, without
terminating this Lease, terminate Tenant's right to possession of the Premises.

              5) If any voluntary or involuntary petition or similar pleading
under any Act of Congress relating to bankruptcy shall be filed by or against
Tenant, or if any voluntary or involuntary proceedings in any court or tribunal
shall be instituted by or against Tenant to declare Tenant insolvent or unable
to pay Tenant's debts, then in any such event, Landlord may, if Landlord so
elects, with or without notice of such election and with or without entry or
other action, by Landlord, forthwith terminate this Lease and Tenant's right to
possession of said Premises, and notwithstanding any other provisions hereof
Landlord shall forthwith upon such termination be entitled to recover damages in
an amount equal to the present value (calculated using an interest factor of
6.5% per year) of all the "Rent Adjustments," additional charges, penalties and
Rent reserved in this Lease for the entire residue of the stated Term or renewal
term hereof. At the time of such payment Tenant may elect: i) to reduce the
payment due to Landlord for the present value of future rent by 66% and pay that
reduced amount in full satisfaction of Landlord's claim for future rent but
without the right of any future reimbursement; or ii) pay the full present value
of the future rent and be entitled to receive reimbursement from landlord of
future rent actually received on a monthly basis (after deduction of the costs
of re-renting) but not to exceed each month the amount paid by Tenant for future
rent divided by the number of months in the term for which such amount was paid
by Tenant.

       (b) In addition to, but without limitation or qualification of, any other
right or remedy of the Landlord herein provided, if the Tenant shall default in
the performance of any covenant, condition or stipulation contained in this
Lease, Landlord may, after thirty (30) days written notice to Tenant, or without
notice if, and in Landlord's reasonable opinion, an emergency exists, perform
the same for the account and at the expense of Tenant, and the amount of any
payments made or other expenses incurred by Landlord for such purposes shall be
forthwith repaid by Tenant with interest thereon at the highest per annum rate
allowed by law. Should Tenant, pursuant to this Paragraph, or any other
provision of this Lease, become obligated to reimburse or otherwise pay Landlord
any one or more sums of money in addition to the Rent, the amount thereof shall
be deemed additional rent and may, at the option of Landlord, be added to any
subsequent installment of the Rent due and payable under the Lease; in which
event Landlord shall have the

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remedies for default in termination of this Lease. The provisions of this
Paragraph shall survive the termination of this Lease. Nothing in this Paragraph
shall in any manner increase Landlord's liability to Tenant or to any other
person. The rights granted to Landlord under this Paragraph shall be permissive
only and shall not be construed as requiring Landlord to perform any such
condition or covenant or to correct any such default.

       (c) Upon the termination of this Lease, or upon the termination of
Tenant's right to possession without termination of the Lease:

              1) Tenant shall surrender possession and vacate the Premises
immediately, and Landlord may enter into and repossess said Premises, without or
with process of law, and remove all persons and property therefrom in the same
manner and with the same right as if this Lease had not been made, and for the
purpose of such entry and repossession, Tenant waives any notice provided by
law or otherwise to be given in connection therewith; and

              2) Landlord may remove from the Premises any and all property
found therein and such repossession shall not release Tenant from Landlord's
obligation to pay the Rent herein provided.

       (d) In the event of termination of this Lease as provided in this
paragraph, Landlord in addition to any and all rights and remedies allowed by
law and equity, shall upon termination be entitled to recover damages in the
amount equal to the present value of all the additional charges, "Rent
Adjustments," penalties and Rent in this Lease for the entire residue of the
Term or renewal term hereof after subtracting the reasonable rental value of the
Premises, subject to the same election as provided in paragraph 19(a)5).

       (e) Any and all property which may be removed from the Premises by
Landlord may be handled, removed, stored or otherwise disposed of by Landlord at
the risk and expense of Tenant, and Landlord shall in no event be responsible
for the preservation or the safekeeping thereof. Tenant shall pay to Landlord,
upon demand, any and all expenses incurred in such removal and all storage
charges against such property, so long as the same shall be in Landlord's
possession or under Landlord's control. If any property shall remain in the
Premises or in the possession of Landlord, and shall not be retaken by Tenant
within a period of ten (10) days from and after the time when the Premises are
either abandoned by Tenant or repossessed by Landlord under the terms of this
Lease, said property shall conclusively be deemed to have been forever abandoned
by Tenant.

       20. SUBORDINATION: Tenant understands that Landlord may have placed or
hereafter desire to place a mortgage upon the land described herein and the
Building constructed thereon. It is further understood that the mortgage may
require that the Lease

                                      -12-
<PAGE>   13

be subordinated to said mortgage, in which event Tenant agrees to execute any
document required by such mortgagee to evidence such subordination; provided,
however, that the mortgagee of any mortgage shall covenant that the Tenant's
leasehold interest hereunder shall not be foreclosed in any action brought under
such mortgage (or in any deed in lieu thereof) if at the time of bringing of any
action to foreclose (or upon filing of the deed in lieu thereof), Tenant is not
in default in the payment of rental or in the performance of any other
obligation under this Lease, with due allowance to be given for the payment of
any past due rental or for the correction of any other default by Tenant within
the period of any notice given or required to be given by the terms hereof. It
is further understood that the mortgagee of said mortgage may, subject to
Tenant's non-disturbance rights, require that Tenant agree to attorn to any
purchaser of the property in the event that the same should be sold through
foreclosure proceedings, and that Tenant agrees to waive any and all rights to
treat any such foreclosure proceedings as a breach of the Lease by Landlord, in
which event Tenant agrees to execute any document required by such mortgages to
evidence such agreements.

       21. ESTOPPEL CERTIFICATES: At any time and from time to time Landlord and
Tenant each agree, upon request in writing from the other, to execute,
acknowledge and deliver to the other or to any person designated by the other, a
statement in writing certifying that the Lease is unmodified and in full force
and effect (or if there have been modifications, that the same is in full force
and effect as modified and stating the modifications), that the other party is
not in default in the performance of its covenants hereunder (or if there are
such defaults, specify the same).

       22. NOTICES: Whenever Landlord shall make any demand or serve any notice
which is required to be in writing under the terms of this Lease upon Tenant,
the same shall be in writing and shall be sufficiently given if sent, postage
prepaid, by United States registered or certified mail, addressed to Tenant at
the address as set forth herein, or at such other address as Tenant may last
theretofore by written notice to Landlord have designated for the service of
such notice. Notice shall be sufficiently given or served by Tenant upon
Landlord if sent, postage prepaid, by United States registered or certified
mail, addressed to Landlord at the address set forth herein or at such other
address as Landlord may theretofore by written notice to Tenant have designated
for the service of such notice.

       To Landlord at:           Prairie Warehousing, LLP
                                 P.O. Box 456
                                 Sun Prairie, WI 53590

                                      -13-
<PAGE>   14

       To Tenant at:             Third Wave Technologies, Inc.
                                 502 South Rosa Road
                                 Madison, WI 53719
                                 Attention: President

       23. EMINENT DOMAIN: Tenant agrees with Landlord that if the whole or any
part of said Premises shall be appropriated, condemned, taken or otherwise
acquired by any public or quasi-public authority under the power of eminent
domain, condemnation or other proceedings, this Lease and the estate hereby
created shall terminate and wholly expire on the date title shall vest in the
acquiring authority, and all Rent shall be prorated and adjusted as of said
date. In no event whatsoever shall Tenant have any claim against Landlord by
reason of any appropriation, condemnation or taking of the whole or any part of
said Premises or of said Building, nor shall Tenant have any claim to the amount
or any portion thereof, that may be awarded as damages or paid as a result of
such appropriation and taking. Tenant hereby assigns to Landlord all of Tenant's
right, title and interest in and to any and all amounts awarded or paid by
reason of such appropriation, condemnation and taking, provided however, that
none of the foregoing is meant to deprive Tenant from claiming moving expenses,
displacement expenses, the unamortized portion of leasehold improvements made by
Tenant, damage to Tenant's fixtures or the like solely from the acquiring
authority.

       24. HAZARDOUS MATERIALS: Except as otherwise set forth in this Lease,
Tenant shall not use the leased Premises, the building or the grounds
surrounding the building for the storage or disposal of Hazardous Material or
toxic waste, and Tenant shall indemnify and hold Landlord harmless from any and
all claims, demands, liabilities, costs, expenses, penalties, damages and
losses, including, without limitation, reasonable attorneys fees, resulting from
the existence of Hazardous Materials not caused by Landlord (or Landlord's
agents, employees, contractors or invitees) on the Premises or discharged from
the Premises or penetrating any surface or subsurface rivers or streams crossing
or adjoining the Premises or the aquifer underlying the Premises. Tenant further
covenants that Tenant shall not bury nor inject, nor pour upon the surface or in
or upon the land or into any public or private sewer or drainage facility, any
Hazardous Material or toxic waste. Hazardous Material as used in this Lease
means any hazardous or toxic material, substance or waste which is defined by
those or similar terms or is regulated as such under any statute, law,
ordinance, rule or regulation of any local, state or federal authority having
jurisdiction over the Premises or its use, including but not limited to, any
material, substance or waste which is (a) defined as hazardous substance under
Section 311 of the Federal Water Pollution Control Act (33 U.S.C. Section 1317)
as amended; (b) defined as

                                      -14-
<PAGE>   15

hazardous waste under Section 1004 of the Federal Resource Conservation Recovery
Act (42 U.S.C. Section 6901, et. seq.) as amended; or (c) defined as hazardous
waste substance under Section 101 of the Comprehensive Environmental Response,
Compensation and Liability Act (42 U.S.C. Section 9601, et. seq.) as amended.

       25. NO WAIVER: Any demand for Rent upon Tenant after the same shall have
become due and payable, or for the performance or observation of any covenant or
condition of this Lease after the same is required to be performed or observed
under the provisions hereof, shall have the same effect as though made at the
time and place such Rent became due or such obligation should have been
performed or observed, any law to the contrary notwithstanding.

       (a) The receipt of money by Landlord from Tenant with knowledge of the
breach of any covenants of this Lease, or after the termination hereof, or after
the service of any notice or after the commencement of such suit, or after final
judgment for possession of said Premises shall not be deemed a waiver of such
breach, nor shall it reinstate, continue or extend the Term of this Lease or
affect any such notice, demand or suit.

       (b) No delay on the part of Landlord in exercising any right, power or
privilege hereunder shall operate as a waiver thereof, nor shall any single or
partial exercise of any right, power or privilege preclude any other, or
further, exercise thereof or the exercise of any other right, power or
privilege.

       (c) No act done or thing said by Landlord or Landlord's agents or
employees shall constitute a cancellation, termination or modification of this
Lease, or a waiver of any covenant, agreement or condition hereof, nor relieve
Tenant from Tenant's obligation to pay the Rent or other charges to be paid
hereunder, or the acts required to be done herein. Any waiver or release by
Landlord and any cancellation, termination or modification of this Lease must be
in writing and signed by Landlord.

       26. MEMORANDUM OF LEASE: This Lease shall not be recorded, either
independently or as an exhibit, schedule, annex or addendum to any other
document. However, a Memorandum of Lease, describing the property herein
demised, stating the Initial Term and Renewal Term of this Lease, the names and
addresses of Landlord and Tenant, and referring to this Lease, but containing no
other terms or provisions hereof except as may be agreed upon by the parties
hereto or as may be required by law, promptly shall be executed, acknowledged
and delivered for recording by both parties.

                                      -15-
<PAGE>   16

       27. ENTIRE AGREEMENT: This Lease contains the entire agreement between
the parties hereto and shall not be modified in any manner except by an
instrument in writing executed by said parties or their respective successors in
interest. If more than one person or entity or a combination thereof comprise
"Tenant," their liability hereunder shall be joint and several. Landlord has
made no representations or warranties with respect to the Premises, except as
herein expressly set forth.

       28. PARAGRAPH HEADINGS: The paragraph headings appearing in this Lease
are inserted only as a matter of convenience and for reference purposes, and in
no way define, limit or describe the scope and intent of this Lease, or any
paragraph hereof, nor in any way affect it.

       IN WITNESS WHEREOF, Tenant and Landlord have executed counterparts of
this Lease as of the day, month and year first above shown.

WITNESSES AS TO LANDLORD:               LANDLORD:
/s/ SIGNATURE                           PRAIRIE WAREHOUSING, LLP
--------------------------------
/s/ SIGNATURE                           By: /s/ SIGNATURE
--------------------------------           -------------------------------------
                                           Name:
                                           Title: Partners

WITNESSES AS TO TENAN:                  TENANT:
/s/ SIGNATURE                           THIRD WAVE TECHNOLOGIES, INC.
--------------------------------
/s/ SIGNATURE                           By: /s/ SIGNATURE
--------------------------------           -------------------------------------
                                           Name: Lance Fors
                                           Title: President & CEO

                                      -16-
<PAGE>   17

                           LANDLORD'S ACKNOWLEDGMENT

STATE OF WISCONSIN )
                   )ss.
COUNTY OF DANE     )

       Before me, a Notary Public in and for said county and state, personally
appeared, August J. List, the individual named in the foregoing instrument as
the partner of Prairie Warehousing, LLP, which executed the foregoing instrument
and acknowledged that he did sign the foregoing as a partner and that such
signing is the free act and deed for said partnership for the uses and purposes
therein mentioned.

       IN WITNESS WHEREOF, I have hereunder set my hand and seal this 10th day
of April, 2000.

                                        /s/ SIGNATURE
                                        ----------------------------------------
                                        Notary Public, State of Wisconsin
                                        My Commission expires 6/8/03

                             TENANT'S ACKNOWLEDGMENT

STATE OF WISCONSIN )
                   )ss.
COUNTY OF DANE     )

       Before me, a Notary Public in and for said county and state, personally
appeared Lance Fors, the individual named in the foregoing instrument as the
President and CEO of Third Wave Technologies, Inc., which executed the foregoing
instrument and acknowledged that he did sign the foregoing as an officer and
that such signing is the free act and deed for said corporation for the uses and
purposes therein mentioned.

       IN WITNESS WHEREOF, I have hereunder set my hand and seal this 11th day
of April, 2000.

                                        /s/ SIGNATURE
                                        ----------------------------------------
                                        Notary Public, State of Wisconsin
                                        My Commission expires 1/21/01

                                                          DANA L. LAMB
F:\P\PRAIRIE WAREHOUSING LLP\THIRDWAVE.LEASE.WPD          NOTARY PUBLIC
                                                       STATE OF WISCONSIN

                                      -17-
<PAGE>   18

                                    EXHIBIT A

                                    PREMISES

                                      -18-
<PAGE>   19

                             FIRST ADDENDUM TO LEASE

       THIS FIRST ADDENDUM TO LEASE ("Addendum") is dated for reference purposes
as of April 10, 2000, and is made between Prairie Warehousing, LLP ("Landlord")
and Third Wave Technologies, Inc., a Wisconsin corporation ("Tenant")to be a
part of that certain Lease, of even date herewith between Landlord and Tenant
(herein the "Lease Form") concerning approximately 36,000 square feet of space
(the "Premises"), located at 220 Business Park Drive, Sun Prairie, Wisconsin
(the "Building"). Landlord and Tenant agree that notwithstanding anything in the
Lease Form, the Lease Form is modified and supplemented by this Addendum. Each
term used herein with initial capital letters shall have the meaning ascribed to
such term in the Lease Form unless specifically otherwise defined herein. In the
event of any inconsistency between this First Addendum and the Lease Form, the
terms of this First Addendum shall prevail. As used herein, the term "Lease"
shall mean the Lease Form, this Addendum and all riders, exhibits, rules,
regulations, covenants, conditions and restrictions referred to in the Lease
Form or this Addendum.

       1.PREMISES TERM.

              A. The Lease shall commence (the "Commencement Date") on the date
by which Landlord has delivered possession of the Premises to Tenant. Landlord
shall deliver possession of the Premises to Tenant upon execution of this Lease.
If the Commencement Date has not occurred for any reasons whatsoever on or
before the tenth (10th) day after the parties hereto have fully executed this
Lease, then in addition to Tenant's other rights or remedies, Tenant may
terminate this Lease by written notice to Landlord, whereupon any monies
previously paid by Tenant to Landlord shall be reimbursed to Tenant.

              B. Landlord shall designate the Premises as 220 Business Park
Drive and designate that adjacent space currently occupied by Trek Diagnostics
in the Building as 210 Business Park Drive and shall promptly register these
designations with the United States Post Office.

       4. RENT. Rent for the first sixty (60) days of the Term shall be one-half
the Rent under Section 4 of the Lease (i.e., $9,000 per month). No rent shall be
due for the period from the Commencement Date through April 30, 2000.

       6. TAXES. "Taxes" shall not include and Tenant shall not be required to
pay any portion of any tax or assessment expense or any increase therein (a) in
excess of the amount which would be payable if such tax or assessment expense
were paid in

<PAGE>   20

installments over the longest possible term; (b) imposed on land and
improvements other than the land and improvements on which the leased Premises
and Tenant's parking areas are located; (c) attributable to Landlord's net
income, inheritance, gift, transfer, estate or state taxes; or (d) resulting
from a change of ownership or transfer of any or all of the Building.

       9. USE AND REPAIR OF PREMISES BY TENANT; UTILITIES. Landlord shall
perform and construct, and Tenant shall have no responsibility to perform or
construct, any repair, maintenance or improvement which could be treated as a
"capital expenditure" under generally accepted accounting principles and which
Landlord elects to construct or is required to construct by this Lease (i.e.
two-hour fire wall). Notwithstanding anything contained in the Lease to the
contrary, Tenant shall be solely responsible for constructing, repairing and
maintaining all Tenant construction and leasehold improvements.

       11. RIGHTS RESERVED BY LANDLORD. Landlord, except in the case of
emergency, shall provide Tenant with twenty-four (24) hours' notice prior to
entry of the Premises. Any such entry by Landlord shall comply with all
reasonable security measures of Tenant and shall not impair Tenant's operations
more than reasonably necessary. Landlord shall not exercise its rights under
Section 11 of the Lease if such actions would unreasonably interfere with
Tenant's use of the Premises or increase the obligations or decease the rights
of Tenant under the Lease. In taking such actions, Landlord shall at all times
use its best efforts to minimize any disruption to Tenant.

       14(a). LOSS OR DAMAGE TO PROPERTY. Landlord shall not be released or
indemnified from, and shall indemnify, defend, protect and hold harmless Tenant
from, all losses, damages, liabilities, judgments, actions, claims, attorneys'
fees, consultants' fees, payments, costs and expenses arising from the
negligence or willful misconduct of Landlord or its agents, contractors,
licensees or invitees.

       14(c). LOSS OR DAMAGE TO PROPERTY. If there is any interruption, failure,
stoppage or interference of the utilities or services to the Premises under the
Lease or due to the presence of any Hazardous Materials on or about the Building
(except to the extent released or emitted by Tenant), and such interruption
continues for ten (10) consecutive calendar days, then Tenant shall be entitled
to an equitable abatement of rent to the extent of the interference with
Tenant's use of the Premises occasioned thereby. If the interference persists
for more than forty-five (45) consecutive calendar days, then Tenant shall have
the right to terminate the Lease.

                                      -2-
<PAGE>   21

       16. ASSIGNMENT AND SUBLETTING. Notwithstanding anything to the contrary
in the Lease, Tenant may, without Landlord's prior written consent, sublet the
Premises or assign the Lease to: (i) a subsidiary, affiliate, division or
corporation controlling, controlled by or under common control with Tenant; (ii)
a successor corporation related to Tenant by merger, consolidation,
nonbankruptcy reorganization, or government action; or (iii) a purchaser of
substantially all of Tenant's assets located in the Premises. For the purpose of
this Lease, sale of Tenant's capital stock shall not be deemed an assignment,
subletting, or any other transfer of the Lease or the Premises.

       17. ALTERATIONS. In no event shall Tenant be required to remove the
Initial Improvements from the Premises at the end of the Term.

       18. UNTENANTABILITY. In the event Landlord determines that any
destruction or damage can be reasonably repaired within one hundred twenty (120)
days, but such destruction or damage are not in fact repaired within such
period, Tenant may terminate the Lease by written notice to Landlord within
thirty (30) days after the expiration of such period.

       20. SUBORDINATION. Within thirty (30) days of the Commencement Date,
Landlord shall cause all mortgagees, lenders, ground lessors and other parties
currently holding security interest affecting the Premises or Building to
execute a recognition and nondisturbance agreement which (i) provides that this
Lease shall not be terminated so long as Tenant is not in default under this
Lease and (ii) recognizes all of Tenant's rights under the Lease. Landlord
agrees to diligently attempt to obtain the agreement of Mortgagees and Lenders.
If the Mortgagees and/or Lenders refuse to execute such an agreement, failure to
obtain such and agreement will not be a breach or default of this Lease by
Landlord.

       22. NOTICES. Any notice required under the Lease that is sent by mail
shall be deemed received, if properly addressed, three (3) business days after
any such notice is deposited in the United States mail certified,
postage-prepaid, return-receipt requested.

       24. HAZARDOUS MATERIAL.

              A. To the best knowledge of Landlord, (a) no Hazardous Material is
present in, under or about the Building or the soil, surface water or
groundwater thereof, (b) no underground storage tanks are present in, under or
about the Building, and (c) no

                                      -3-
<PAGE>   22

action, proceeding or claim is pending or threatened regarding the Building
concerning any Hazardous Material or pursuant to any environmental law. Under no
circumstance shall Tenant be liable for, and Landlord shall indemnify, defend,
protect and hold harmless Tenant, its agents, contractors, stockholders,
directors, successors, representatives, and assigns from and against, all
losses, costs, claims, liabilities and damages (including attorneys' and
consultants' fees) of every type and nature, directly or indirectly arising out
of or in connection with any Hazardous Material present on the Commencement Date
in, under or about the Building, or the soil, air, improvements, groundwater or
surface water thereof, or the violation of any laws, orders or regulations,
relating to any such Hazardous Material, and to the extent that any of the
foregoing actually results from the release or emission of Hazardous Material by
Landlord or its agents or employees after the Commencement Date in violation of
applicable environmental laws.

              B. Tenant shall be entitled to use and store in or adjacent to the
Premises Hazardous Material necessary for the operation of its business on the
Premises. Any storage outside the building must be approved by the Landlord,
City and Business Park Covenant Review Committee and all costs associated with
City or Covenant Committee approval shall be paid by Tenant. Landlord hereby
approves of Tenant's construction of a chemical storage vault in the Premises.

       29. LANDLORD DEFAULT. In the event Landlord fails to perform any of its
obligations under this Lease and (except in case of emergency posing an
immediate threat to persons or property, in which case no prior notice shall be
required) fails to cure such default within thirty (30) days after written
notice from Tenant specifying the nature of such default where such default
could reasonably be cured within said thirty (30) day period, or fails to
commence such cure within said thirty (30) day period and thereafter
continuously with due diligence prosecute such cure to completion where such
default could not reasonably be cured within said thirty (30) day period, then
Tenant may, in addition to its other remedies, cure any default of Landlord at
Landlord's cost and deduct the cost of such cure from Rent, but in no event
shall such deductions during any twelve (12) month period exceed the sum of
three (3) months' Rent accruing during such period. The deductions from Rent
described in the foregoing sentence shall be in addition to all other offsets,
credits, abatements and reductions of or against rent to which Tenant may from
time to time be entitled under this Lease. If Tenant at any time by reason of
Landlord's default reasonably pays any sum or does any act that requires the
payment of any sum, the sum paid by Tenant shall be immediately due from
Landlord to Tenant at the time the sum is paid. Any and all rights and remedies
herein created for Tenant shall be cumulative and

                                      -4-
<PAGE>   23

use of one remedy shall not be taken to exclude or waive the right to the use of
another and Tenant shall have the remedies available to Tenant under applicable
law.

       30. REASONABLE EXPENDITURES. Any expenditure by a party permitted or
required under the Lease, for which such party is entitled to demand and does
demand reimbursement from the other party, shall be limited to the fair market
value of the goods and services involved, shall be reasonably incurred, and
shall be substantiated by documentary evidence available for inspection and
review by the other party or its representative during normal business hours.

       31. CONDITION OF PREMISES. Landlord warrants and represents that as of
the Commencement Date the Premises will be in good condition and repair, the
roof shall be in good condition and watertight, and the electrical, mechanical,
HVAC, plumbing, elevator and other systems serving the Premises will be in good
condition and repair. The parties acknowledge that the electrical service to the
Premises may not be adequate for 800 amp service. Tenant intends to install a
1600 amp service. Installation of the 1600 amp service will be at Tenant's sole
expense. Landlord shall be responsible for and pay the cost of the abandonment
and removal (if required by the utility or building inspector) of the existing
electric service to the Premises.

       32. NO LIEN. Trade fixtures, furniture, equipment and other personal
property installed in the Premises ("Tenant's Property") shall at all times be
and remain Tenant's property. Tenant may at any time remove Tenant's Property
from the Premises, provided that Tenant repairs all damage caused by such
removal. Landlord shall have no security interest or lien on any item of
Tenant's Property. Landlord waives any right of distraint, distress for rent or
Landlord's lien that may arise at law.

       33. COMPLIANCE WITH LAWS. Tenant shall not be required to comply with or
cause the Premises to comply with any laws, rules or regulations requiring
alterations or improvements unless the compliance with any of the foregoing is
necessitated solely due to Tenant's particular use of the Premises or Tenant's
construction on the Premises.

       34. IMPROVEMENTS.

              A. Landlord shall perform, at its sole cost and expense, in a good
and workmanlike manner and in compliance with all laws, the following
alterations and improvements to the Building (the "Landlord Work"): (1) install
a two-hour rated fire wall to demise the space; (2) "cap" of all plumbing in the
space; (3) secure safely all electrical

                                      -5-
<PAGE>   24

disconnects; (4) ensure that the heating and air conditioning systems is in good
working condition as of the Commencement Date (but shall not be required to
install larger or additional units to increase capacity); (5) replace and
decontaminate all filters and existing duct work (or provide documentation that
such replacement and decontamination has already been completed); and (6) clear
power panel from lockouts. Landlord shall complete item (1) of this Section 34
on or before the thirtieth (30th) day after full execution of this Lease.
Landlord shall complete items (2) through (6) on or before the sixtieth (60th)
day after full execution of this Lease. In the event any such items are not
completed by Landlord on or before such dates and Landlord fails for 10 days
after receiving written notice from Tenant that such work remains unfinished
after said 30 day or 60 day period as applicable to finish said work, Tenant may
complete such items and deduct the cost thereof from Rent next due.

              B. Landlord acknowledges that Tenant will be constructing certain
improvements in the Premises necessary for the operation of its business in the
Premises (the "Initial Improvements"). Landlord hereby approves of the Initial
Improvements described on the preliminary plans and specifications attached to
the Lease as Exhibit B.

              C. In the event Tenant is unsuccessful in obtaining all required
consents, approvals and permits under the Lease and under applicable law in
connection with the Initial Improvements or in connection with the operation of
Tenant's business in the Premises, or in the event Tenant determines in its sole
discretion that it cannot obtain all such consents, approvals and permits in a
commercially reasonable manner, then Tenant may terminate this Lease upon thirty
(30) days written notice, provided such written notice to terminate the Lease is
delivered to Landlord on or before August 1, 2000.

       35. RIGHT OF FIRST OFFER. If Landlord from time to time determines to
lease any space in the building outside of the Premises (each space an
"Expansion Space"), then Landlord shall first notify Tenant of the terms on
which Landlord is willing to lease such Expansion Space. If Tenant, within five
(5) business days after receipt of Landlord's written notice indicates in
writing its agreement to lease the Expansion Space on the terms stated in
Landlord's notice, then Landlord shall lease to Tenant and Tenant shall lease
from Landlord the Expansion Space on the terms stated in Landlord's notice. If
Tenant does not indicate in writing its agreement to lease the Expansion Space
on the terms contained in Landlord's notice within said five (5) business day
period, then Landlord thereafter shall have the right to lease such Expansion
Space to a third party on the same terms stated in Landlord's notice. If
Landlord does not lease the Expansion Space within ninety (90) days after the
expiration of said five (5) business day period, any further transaction shall
be deemed a new determination by Landlord to lease such Expansion

                                      -6-
<PAGE>   25

Space and the provisions of this paragraph shall again be applicable with
respect to such Expansion Space.

       36. INSTALLATION OF GENERATOR. Tenant shall have the right to install,
maintain and operate, at no additional Rent to Tenant, a back-up power generator
and diesel fuel tank in the location shown on Exhibit B attached to the Lease or
such other location as approved reasonably acceptable to Landlord. The generator
shall at all times be and remain an item of Tenant's Property and shall not be
considered an alteration, addition or improvement under Section 17 of the Lease.
Tenant may at any time remove the generator from its location, provided that
Tenant repairs all damage caused by such removal. Tenant shall pay all costs
associated with compliance with all laws, regulations and restrictive covenants,
including but not limited to, construction of required spill prevention, noise
abatement and visual screening.

       37. SIGNAGE. Tenant shall be entitled to install, at its sole cost and
expense, monument signage in the lawn area of the building for its exclusive use
with the design and specifications reasonably acceptable to Landlord. Tenant
shall also be entitled, at its sole cost and expense, to building exterior
signage bearing Tenant's name and corporate logo with a location, design and
specifications reasonably acceptable to Landlord. All signage must be in
compliance with and approved by the City of Sun Prairie and the business park
covenant review committee.

LANDLORD:                               TENANT:
PRAIRIE WAREHOUSING, LLP                THIRD WAVE TECHNOLOGIES, INC.
                                        a Wisconsin corporation

By: /s/ AUGUST J. LIST                  By: /s/ LANCE FORS
   ---------------------------------       -------------------------------------

Printed Name: August J. List            Printed Name: Lance Fors
             -----------------------                 ---------------------------

Title: Partner                          Title: President & CEO
      ------------------------------          ----------------------------------

Date: 4-10-00                           Date: 4-11-00
     -------------------------------         -----------------------------------

                                      -7-
<PAGE>   26

                                    EXHIBIT B

                              INITIAL IMPROVEMENTS

                                      -8-<PAGE>

                                                                    Exhibit 10.4

                                AMENDMENT NO. 1
                                ---------------
                                      TO
                                      --
                            SHAREHOLDERS' AGREEMENT
                            -----------------------
                                      OF
                                      --
                               KIRIN-AMGEN, INC.
                               -----------------

     THIS AMENDMENT NO. 1 TO THAT CERTAIN SHAREHOLDERS' AGREEMENT OF KIRIN-
AMGEN, INC., DATED MAY 11, 1984 ("Amendment No. 1") is made and entered into
this 19th day of March, 1985, by and among KIRIN BREWERY COMPANY, LTD., a
Japanese corporation ("Kirin"), AMGEN, a California corporation ("Amgen"), and
KIRIN-AMGEN, INC., a California corporation ("Corporation").

                                 R E C I T A L
                                 - - - - - - -

     Pursuant to Paragraph 22.19 of the Shareholders' Agreement regarding
expansion of the business of Corporation, the parties hereto desire Corporation
to purchase from Amgen the worldwide rights to EPO Human Diagnostic and Reagent
as an expansion of the Field of Activity as defined in the Shareholders'
Agreement in accordance with the terms and conditions set forth below and to
license the same to Kirin for the territory of Japan and to Amgen for the
territory of the United States of America and its territories and possessions.

     NOW, THEREFORE, it is agreed as follows:

1.   EPO HUMAN DIAGNOSTIC AND REAGENT RIGHTS:EXPANSION OF FIELD: OF ACTIVITY AND
     ---------------------------------------------------------------------------
     BUSINESS OPPORTUNITIES
     ----------------------

     Corporation hereby agrees to purchase the worldwide rights to EPO Human
Diagnostic and Reagents ("Diagnostic Rights") from Amgen for a price of (U.S.)
$1,000,000. This purchase shall constitute an expansion of the Field of Activity
as defined in the Shareholder's Agreement, and in accordance with Paragraph
22.19 of the Shareholders' Agreement, shall also constitute the first additional
opportunity for mutual development of other products and areas of interest by
Kirin, Amgen and Corporation.

2.   PURCHASE, PAYMENT OF PURCHASE PRICE AND TRANSFER OF DIAGNOSTI RIGHTS
     --------------------------------------------------------------------

     Corporation shall promptly pay Amgen (U.S.) $1,000,000 for the Diagnostic
Rights concurrently with the delivery by Amgen to Corporation of the Assignment
and License Agreement attached hereto as Exhibit "A" together with the physical
transfer of assets comprising the Diagnostic Rights.
<PAGE>

3.   REPRESENTATIONS AND WARRANTIES OF AMGEN REGARDING DIAGNOSTIC
     ------------------------------------------------------------
     RIGHTS
     ------

     As of March 19, 1985, Amgen has valid legal title to and will vest in
Corporation valid legal title to all Diagnostic Rights free and clear of any and
all liens, claims, security interests, encumbrances and restrictions.

4.   CONSISTENCY WITH SHAREHOLDERS' AGREEMENT
     ----------------------------------------

     The rights and obligations of the parties in this Amendment No. 1 with
respect to this expansion of business opportunity shall be consistent with the
provisions of the Shareholders' Agreement.

5.   KIRIN LICENSE
     -------------

     Kirin shall pay Corporation (U.S.) $200,000, which payment shall entitle
Kirin to a fully-paid exclusive license in Kirin's territory of Japan with
respect to the Diagnostic Rights in accordance with the License Agreement
attached hereto as Exhibit "B."

6.   AMGEN LICENSE
     -------------

     Amgen shall pay Corporation (U.S.) $200,000, which payment shall entitle
Amgen to a fully-paid exclusive license in Amgen's territory of the United
States and its territories and possessions with respect to the Diagnostic Rights
in accordance with the License Agreement attached hereto as Exhibit "C."

7.   FURTHER INSTRUMENTS
     -------------------

     Each party hereto agrees to perform any and all further acts and execute
and deliver any and all further documents and/or instruments which may be
reasonable or necessary to carry out the provisions of this Amendment No. 1 to
the Shareholders' Agreement and to carry out this further business purpose of
Corporation.

                                      -2-
<PAGE>

     IN WITNESS WHEREOF, the undersigned have caused this Amendment to be
executed on March 19, 1985 by their duly authorized representatives in the
manner legally binding upon them

                              KIRIN BREWERY COMPANY, LTD.,
                              a Japanese corporation

                              By  /s/ Shinkichi Kubo
                                  ----------------------------------------------
                                  Shinkichi Kubo, Managing Director

                                                   "Kirin"

                              AMGEN, a California corporation

                              By  /s/ George B. Rathmann
                                  ----------------------------------------------
                                  George B. Rathmann, President

                                                   "Amgen"

                              KIRIN-AMGEN, INC., a California corporation

                              By  /s/ Tatsuhiko Kaneko
                                  ----------------------------------------------

                                    ____________ Its ______________

                                                   "Corporation"

                                      -3-
<PAGE>

                                                                       Exhibit A

              ___________________________________________________

                       ASSIGNMENT AND LICENSE AGREEMENT

                                by and between

                                    AMGEN,

                           a California corporation,

                                      and

                              KIRIN-AMGEN, INC.,

                           a California corporation

              __________________________________________________
<PAGE>

                               TABLE OF CONTENTS
                               -----------------

<TABLE>
<CAPTION>
                                                                                                Page
                                                                                                ----
<S>                                                                                             <C>
RECITALS...................................................................................       1

I.       TRANSFER AND LICENSE OF TECHNOLOGY................................................       2

         1.01     Assignment of Diagnostic Rights Transferred Technology...................       2
         1.02     License of Diagnostic Rights Core Technology.............................       2
         1.03     Right to Sublicense the Diagnostic Rights Core Technology................       3
         1.04     Limitations..............................................................       4

II.      DEFINITIONS.......................................................................       4

         2.01     Incorporation by Reference...............................................       4
         2.02     Diagnostic Rights Field of Activity/Diagnostic Rights Technology.........       4

III.     DISCLOSURE OF DIAGNOSTIC RIGHTS CORE TECHNOLOGY...................................       5

         3.01     Limitation on Usage......................................................       5
         3.02     Survival.................................................................       5

IV.      PATENT, COPYRIGHT AND TRADE SECRET ENFORCEMENT....................................       5

         4.01     Enforcement..............................................................       5
         4.02     Notice of Infringements..................................................       6

V.       PATENT APPLICATIONS AND COPYRIGHT REGISTRATIONS...................................       7

         5.01     Applications.............................................................       7

VI.      DISCLAIMER OF INDEMNIFICATION.....................................................       7

         6.01     Disclaimer of Warranties.................................................       7
</TABLE>

                                      -i-
<PAGE>

                               TABLE OF CONTENTS
                               -----------------
                                  (Continued)

<TABLE>
<CAPTION>
                                                                                         Page
                                                                                         ----
<S>                                                                                      <C>
VII.     TERM AND TERMINATION........................................................      8

         7.01      Term..............................................................      8
         7.02      Default...........................................................      8
         7.03      Continuing Obligations............................................      9

VIII.    CONSISTENCY WITH SHAREHOLDERS' AGREEMENT....................................      9

         8.01      Shareholders' Agreement...........................................      9

IX.      CONSENTS AND APPROVALS......................................................     10

         9.01      Best Efforts......................................................     10

X.       NOTICE......................................................................     10

         10.01     Notices...........................................................     10

XI.      MISCELLANEOUS...............................................................     12

         11.01     Entire Agreement..................................................     12
         11.02     Headings..........................................................     12
         11.03     Execution in Counterparts.........................................     12
         11.04     Force Majeure.....................................................     12
         11.05     Applicable Law....................................................     13
         11.06     Assignment on Written Consent.....................................     13
         11.07     Severability......................................................     13
         11.08     No Waiver.........................................................     13
         11.09     Trademarks and Tradenames.........................................     13
         11.10     Indemnity.........................................................     14
         11.11     Other Agreements..................................................     14
         11.12     Attorneys' Fees and Costs.........................................     14
         11.13     Remedies..........................................................     15
         11.14     Binding Effect....................................................     15
         11.15     Exhibits..........................................................     15
         11.16     Number and Gender.................................................     16
         11.17     Representations...................................................     16
         11.18     Agreement to Perform Necessary Acts...............................     16
</TABLE>

                                     -ii-
<PAGE>

                       ASSIGNMENT AND LICENSE AGREEMENT
                       --------------------------------

          THIS ASSIGNMENT AND LICENSE AGREEMENT ("Agreement") is made this 4th
day of December, 1985, and is made effective as of the 27th day of June, 1985,
by and between AMGEN, a California corporation ("Amgen"), in favor and for the
benefit of and with KIRIN-AMGEN, INC., a California corporation ("Company"),
pursuant to terms and conditions of that certain Shareholders' Agreement, dated
May ll, 1984, as amended by Amendment No. 1, dated March 19, 1985
("Shareholders' Agreement"), by and among Amgen, Company and Kirin Brewery
Company, Ltd., a Japanese corporation ("Kirin").

                                R E C I T A L S
                                - - - - - - - -

     A.  Pursuant to Paragraph 22.19 of the Shareholders' Agreement regarding
expansion of the business of Corporation, the parties hereto desire Company to
purchase from Amgen the worldwide rights to EPO Human Diagnostics and Reagents
(not including non-human veterinary purposes) ("Diagnostic Rights Field of
Activity and/or Diagnostic Rights) as an expansion of the Field of Activity as
defined in the Shareholders' Agreement in accordance with the terms and
conditions set forth below and to license the same to Kirin for the territory of
Japan and to Amgen for the territory of the United States of America and its
territories and possessions.
<PAGE>

     B.  Company hereby agrees to purchase and license the worldwide Diagnostic
Rights from Amgen for a price of One Million Dollars U.S. ($1,000,000). This
purchase shall constitute an expansion of the Field of Activity as defined in
the Shareholder's Agreement, and in accordance with Paragraph 22.19 of the
Shareholders' Agreement.

NOW, THEREFORE, it is agreed as follows:

                                   ARTICLE I
                                   ---------

                      TRANSFER AND LICENSE OF TECHNOLOGY
                      ----------------------------------

          1.01  Assignment of Diagnostic Rights Transferred Technology. Amgen
                ------------------------------------------------------
hereby transfers and assigns to the Company, perpetually and irrevocably, all of
its right, title and interest in and to the Diagnostic Rights Transferred
Technology, as specifically set forth in Schedule "A" attached hereto, and
agrees to execute all documents necessary to effectuate the legal transfer of
legal title thereto and assignment to the Company, including but not limited to
an assignment of the patents applications, and any inventions disclosed therein,
and intangibles to be recorded with the United States Patent and Trademark
Office.

          1.02  License of Diagnostic Rights Core Technology. Amgen hereby
                --------------------------------------------
grants to the Company a royalty-free, perpetual and exclusive right and license
throughout the world in and to all of

                                      -2-
<PAGE>

the Diagnostic Rights Core Technology solely with respect to its direct
application to the Diagnostic Rights Field of Activity.

          1.03  Right to Sublicense the Diagnostic Rights Core Technology.
                ---------------------------------------------------------
Amgen also hereby grants to the Company royalty-free the right to grant
sublicenses within and limited to the scope of the right and license granted to
the Company in Section 1.02 only, (a) to Kirin under that certain License
Agreement between the Company and Kirin, dated of even date herewith, (b) to any
subsidiary of the Company, (c) to a single manufacturer in addition to Kirin and
Amgen for the account of the Company outside of the Amgen Territory and Kirin
Territory, and (d) to licensees of the Company under patents, know-how or
materials owned by the Company to the extent such licensees require any such
sublicense in order to practice the patents or know-how or to use the materials
that are the subject of the license from the Company, provided, however, that no
sublicense shall be granted under clause (d) hereof without the prior written
consent (not to be unreasonably withheld) of Amgen.  Any sublicensees of the
Company shall undertake in writing to be bound by the provisions of Sections
3.01 and 3.02 hereof to the same extent the Company is bound.  The Company shall
notify Amgen of the identity of each sublicensee to whom a sublicense is granted
and provide Amgen a true and correct copy of such sublicense.  In the event that
the license granted to the

                                      -3-
<PAGE>

Company is terminated at any time in accordance with Article VII, and Amgen
shall not be in default under Section 7.02 hereof, Amgen shall have the option
to terminate or to have the Company assign to Amgen, retroactive to the date of
termination, any sublicenses granted hereunder by the Company to any subsidiary
of the Company. The Company shall include in all its sublicenses granted
hereunder to any subsidiary of the Company provisions for such termination and
assignment.

          1.04  Limitations. No right or license is granted to the Company
                -----------
hereunder except as expressly specified in Sections 1.01, 1.02 and 1.03 hereof.

                                  ARTICLE II
                                  ----------

                                  DEFINITIONS
                                  -----------

          2.01  Incorporation by Reference. The definitions of terms contained
                --------------------------
in the Shareholders' Agreement are hereby incorporated by reference.

          2.02  Diagnostic Rights Field of Activity/Diagnostic Rights
                -----------------------------------------------------
Technology.  Diagnostic Rights Field of Activity/Diagnostic Rights Technology
----------
shall mean the areas of development manufacture, production, use and worldwide
commercial sale of EPO human diagnostic and/or reagent products and shall
exclude non-human veterinary purposes.

                                      -4-
<PAGE>

                                  ARTICLE III
                                  -----------

                DISCLOSURE OF DIAGNOSTIC RIGHTS CORE TECHNOLOGY
                -----------------------------------------------

          3.01  Limitation on Usage. Except as expressly authorized by this
                -------------------
Agreement or by other written consent of Amgen, for the term of this Agreement
and thereafter, the Company shall not deliver, transmit or provide to any person
other than to a sublicensee under a license granted in accordance with Section
1.03, and shall not use, any of the Diagnostic Rights Core Technology owned by
Amgen, or authorize, cause or aid anyone else to do so. Except as provided in
Section 1.03 above, nothing in this Agreement shall be deemed to give the
Company any right or license to use or to replicate or reproduce any of the
Diagnostic Rights Core Technology owned by Amgen, or to authorize, aid, or cause
others so to do.

          3.02  Survival. The obligation of confidentiality imposed by the
                --------
foregoing Section 3.01 shall survive termination of this Agreement for any
reason whatsoever.

                                  ARTICLE IV
                                  ----------
                PATENT, COPYRIGHT AND TRADE SECRET ENFORCEMENT
                ----------------------------------------------

          4.01  Enforcement. Amgen shall have the right to bring, defend and
                -----------
maintain, and the Company shall have the right, but not the obligation, to join
in, any appropriate suit or action

                                      -5-
<PAGE>

involving infringement of any patents or copyrights, misappropriation of any
trade secrets or interference with any Diagnostic Rights Core Technology
licensed to the Company in the Diagnostic Rights Field of Activity pursuant to
this Agreement. If Amgen declines to enforce any patent, trade secret or other
right, then in such event, the Company and/or Kirin shall each have the right,
but not the obligation to bring any such action. If the Company or Kirin finds
it necessary to join Amgen in such suit or action, Amgen shall execute all
papers and perform such other acts as may be reasonably required and may, at its
option, be represented by counsel of its choice. The Company or Kirin, whichever
brings the action, shall pay to Amgen its reasonable expenses (excluding its
attorney's fees) in connection with any such suit or action. Should the Company
or Kirin, whichever brings the action, lack standing to bring any such action
then the Company or Kirin may cause Amgen to do so upon first undertaking to
indemnify and hold Amgen harmless (to the extent permissible by law) from all
consequent liability and to promptly reimburse all reasonable expenses
(including attorney fees) stemming therefrom. Any amount recovered in any such
action or suit, whether by judgment or settlement, shall be paid to or retained
entirely by the Company or Kirin, whichever brought the action.

          4.02  Notice of Infringements.  Either party hereto shall provide the
                -----------------------
other with reasonable notice of the evidence and

                                      -6-
<PAGE>

existence of third parties, who come to the attention of such party, who may be
involved in activities which infringe or potentially infringe, misappropriate or
potentially misappropriate or interfere with patents, copyrights, trade secrets
concerning the Diagnostic Rights Core Technology licensed to the Company
pursuant to this Agreement.

                                   ARTICLE V
                                   ---------

                PATENT APPLICATIONS AND COPYRIGHT REGISTRATIONS
                -----------------------------------------------

          5.01  Applications. Amgen shall have the obligation of prosecuting and
                ------------
maintaining in force patent applications or patents and copyright registrations
or copyrights, if any, of the Diagnostic Rights Core Technology, and any costs
thereby incurred shall be borne by Amgen.

                                  ARTICLE VI
                                  ----------

                         DISCLAIMER OF INDEMNIFICATION
                         -----------------------------

          6.01  Disclaimer of Warranties. AMGEN EXPRESSLY DISCLAIMS ALL
                ------------------------
WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE WITH RESPECT TO THE
DIAGNOSTIC RIGHTS TRANSFERRED TECHNOLOGY AND LICENSED DIAGNOSTIC RIGHTS CORE
TECHNOLOGY TO BE FURNISHED BY AMGEN TO THE COMPANY HEREUNDER.

                                      -7-
<PAGE>

                                  ARTICLE VII
                                  -----------

                             TERM AND TERMINATION
                             --------------------

          7.01  Term. This Agreement (including the license and rights granted
                ----
under Sections 1.02 and 1.03 hereof) shall come into effect as of June 27, 1985
and shall remain in full force and effect until the earlier of (a) the
liquidation or dissolution of the Company other than in connection with a
continuation of the business of the Company in some other legal form, or (b)
termination pursuant to Section 7.02.

          7.02  Default. In the event that the Company or Amgen (the "Defaulting
                -------
Party") shall (a) default in a material obligation hereunder and fail to remedy
such default within sixty (60) days after such default shall have been called to
its attention by a notice in writing from the non-breaching party, (b) become
bankrupt or insolvent, or file a petition in bankruptcy or make a general
assignment for the benefit of creditors or otherwise acknowledge insolvency, or
be adjudged bankrupt, (c) go or be placed in a process of complete liquidation
other than in connection with a continuation of the business of the Company in
some other legal form, or (d) suffer the appointment of a receiver for any
substantial portion of its business who shall not be discharged within sixty
(60) days after his appointment, then, and in any such event, the non-breaching
party, at its option, may terminate its

                                      -8-
<PAGE>

obligations to and the rights of the Defaulting Party under the license to the
Diagnostic Rights Core Technology granted under this Agreement upon ten (10)
days' written notice to the Defaulting Party, which termination shall be
effective as of the occurrence of the event giving rise to the option to
terminate.

          7.03  Continuing Obligations. Notwithstanding the termination of a
                ----------------------
party's obligations to or the rights of the Defaulting Party under this
Agreement in accordance with the provisions of Section 7.01 or 7.02, the
provisions of Sections 3.01 and 3.02, this Section 7.03 and Article VIII hereof
shall survive such termination and continue in full force and effect for an
indefinite term. Upon termination of this Agreement for any reason, and without
limitation of other remedies, the Company shall immediately return to Amgen (to
the extent such return is technically feasible) all materials relating to the
Diagnostic Rights Core Technology in the possession of the Company or its
subsidiaries, or of which the Company shall have the right to regain possession
or, at the sole election of Amgen, shall destroy such material (to the extent
technically feasible).

                                 ARTICLE VIII
                                 ------------

                   CONSISTENCY WITH SHAREHOLDERS' AGREEMENT
                   ----------------------------------------

          8.01  Shareholders' Agreement. This assignment of the Diagnostic
                -----------------------
Rights Transferred Technology and license of the

                                      -9-
<PAGE>

Diagnostic Rights Core Technology is granted pursuant to Amendment No. 1 of the
Shareholders' Agreement and shall be governed by the provisions thereof to the
extent applicable. To the extent that there may be conflicts or inconsistencies
between the provisions of this Agreement and those contained in the
Shareholders' Agreement and Amendment No. 1 thereto, the provisions of the
Shareholders' Agreement and Amendment No. 1 thereto shall prevail and govern
interpretation.

                                  ARTICLE IX
                                  ----------

                            CONSENTS AND APPROVALS
                            ----------------------

          9.01  Best Efforts. The parties hereto shall use their best efforts to
                ------------
obtain as soon as practicable any and all consents, approvals, orders or
authorizations required to be obtained from any governmental authority with
respect to the provisions hereof.

                                   ARTICLE X
                                   ---------

                                    NOTICE
                                    ------

         10.01  Notices. All notices, requests, demands and other communications
                -------
required or permitted to be given under this Agreement shall be in writing and
shall be mailed to the Party to whom notice is to be given, by telex or
facsimile, and confirmed by first class mail, registered or certified, return

                                     -10-
<PAGE>

receipt requested, postage prepaid, and properly addressed as follows (in which
case such notice shall be deemed to have been duly given on the third (3rd) day
following the date of such sending):

     "Amgen"             Amgen
                         1900 Oak Terrace Lane
                         Thousand Oaks, CA 91320
                         U.S.A.
                         Telex No. 4994440 (AMGEN)
                         Attn: Corporate Secretary

     With a copy to:     Cooley, Godward, Castro,
                         Huddleson & Tatum
                         One Maritime Plaza, 20th Floor
                         San Francisco, CA 94111
                         U.S.A.
                         Telex No. 910-372-7370 Cooley SFO
                         Attn: Alan C. Mendelson, Esq.

     "Company"           Kirin-Amgen, Inc.
                         1900 Oak Terrace Lane
                         Thousand Oaks, CA 91320
                         U.S.A.
                         Telex No. 4994440 (AMGEN)
                         Attn: Corporate Secretary

     With a copy to:     Musick, Peeler & Garrett
                         One Wilshire Boulevard
                         Suite 2000
                         Los Angeles, CA 90017
                         U.S.A.
                         Telex No. 701357 (MPG LAW UD)
                         Attn: Joel S. Marcus, Esq.

Any Party by giving notice to the others in the manner provided above may change
such Party's address for purposes of this Paragraph 10.01.

                                     -11-
<PAGE>

                                  ARTICLE XI
                                  ----------

                                 MISCELLANEOUS
                                 -------------

          11.01  Entire Agreement. This Agreement, together with any other
                 ----------------
written agreements between the parties hereto referred to in the Shareholders'
Agreement and Amendment No. 1, set forth the entire agreement of the parties
with respect to the subject matter hereof and may not be modified except by a
writing signed by authorized representatives of the parties hereto.

          11.02  Headings.  Article and section headings in this Agreement are
                 --------
included for convenience of reference only and shall not constitute a part of
this Agreement for any other purpose.

          11.03  Execution in Counterparts.  This Agreement may be executed in
                 -------------------------
any number of counterparts and by different parties hereto in separate
counterparts each of which when so executed and delivered shall be deemed to be
an original and all of which counterparts of this Agreement taken together shall
constitute but one and the same instrument.

          11.04  Force Majeure.  It is agreed that each of the parties hereto is
                 -------------
excused from performing such acts as are required hereunder as may be prevented
by or whose purpose is frustrated by Force Majeure.  The party so affected shall
give notice to the other party in writing promptly and thereupon shall

                                     -12-
<PAGE>

be excused from such of its obligations hereunder as it is unable to perform on
account of the Force Majeure throughout the duration thereof plus a period of
thirty (30) days.

          11.05  Applicable Law. This Agreement shall be governed by and
                 --------------
construed in accordance with the laws of the State of California.

          11.06  Assignment on Written Consent. This Agreement may not be
                 -----------------------------
assigned in whole or in part by Amgen or the Company, except with the prior
written consent of the other party.

          11.07  Severability. In the event any one or more of the provisions
                 ------------
contained in this Agreement shall be invalid, illegal or unenforceable in any
respect, the validity, legality and/or enforceability of the remaining
provisions contained herein shall not in any way be affected or impaired
thereby. In such event, such invalid provision or provisions shall be validly
reformed to as nearly approximate the intent of the parties as possible and if
unreformable, shall be severed and deleted from this Agreement.

          11.08  No Waiver. No failure or delay on the part of either party in
                 ---------
exercising any right, power or remedy hereunder shall operate as a waiver
thereof; nor shall any single or partial exercise of any such right, power or
remedy preclude any other or further exercise thereof or the exercise of any
other right, power or remedy hereunder or the remedies provided by law.

                                     -13-
<PAGE>

          11.09  Trademarks and Tradenames. Amgen grants no rights to the
                 -------------------------
Company in any trademarks or tradenames of Amgen or of any of its respective
subsidiaries or affiliated companies.

          11.10  Indemnity. The Company hereby (a) releases Amgen from any
                 ---------
obligation to defend, indemnify or save the Company and its agents and employees
harmless from and (b) agrees to defend, indemnify and save Amgen harmless from
any and all costs, expenses (including attorneys' fees), liabilities, damages
and claims for any injury or death to persons or damage to or destruction of
property, or other loss, arising out of or in connection with any product made,
used or sold by the Company or the use by the Company of any Transferred or
Licensed Technology furnished pursuant to any provision hereunder.

          11.11  Other Agreements. Any other provision of this Agreement
                 ----------------
notwithstanding, nothing in this Agreement shall obligate Amgen to disclose to
the Company any information or to make available to the Company any materials in
violation of an obligation of secrecy or a limitation of use imposed by a third
party from whom such information or materials shall have been received.

          11.12  Attorneys' Fees and Costs. In the event of any action at law or
                 -------------------------
in equity between the Parties hereto to enforce any of the provisions hereof,
the unsuccessful party or parties to such litigation shall pay to the successful
party or parties

                                     -14-
<PAGE>

all costs and expenses, including actual attorneys' fees, incurred therein by
such successful party or parties; and if such successful party or parties shall
recover judgment in any such action or proceeding, such costs, expenses and
attorneys' fees may be included in and as part of such judgment. The successful
party shall be the party who is entitled to recover its costs of suit, whether
or not the suit proceeds to final judgment. A party not entitled to recover its
costs shall not recover attorneys' fees.

          11.13  Remedies. No right, power or remedy herein conferred upon or
                 --------
reserved to any Party is intended to be exclusive of any other right, power or
remedy or remedies, and each and every right, power and remedy of any Party
pursuant to this Agreement or now or hereafter existing at law or in equity or
by statute or otherwise shall to the extent permitted by law be cumulative and
concurrent, and shall be in addition to every other right, power or remedy
pursuant to this Agreement, or now or hereafter existing at law or in equity or
by statute or otherwise and the exercise or beginning of the exercise by any
Party of any one or more of such rights, powers or remedies shall not preclude
the simultaneous or later exercise by any Party of any or all such other rights,
powers or remedies.

                                     -15-
<PAGE>

          11.14  Binding Effect. This Agreement shall be binding upon and inure
                 --------------
to the benefit of the Parties hereto, their successors and assigns.

          11.15  Exhibits. The schedule attached hereto and referred to herein
                 --------
is hereby incorporated herein as though fully set forth at length.

          11.16  Number and Gender. Words in the singular shall include the
                 -----------------
plural, and words in a particular gender shall include either or both additional
genders, when the context in which such words are used indicates that such is
the intent.

          11.17  Representations. Each of the Parties hereto acknowledges and
                 ---------------
agrees (i) that no representation or promise not expressly contained in this
Agreement has been made by any other Party hereto or by any of its agents,
employees, representatives or attorneys; (ii) that this Agreement is not being
entered into on the basis of, or in reliance on, any promise or representation,
expressed or implied, covering the subject matter hereof; other than those which
are set forth expressly in this Agreement; and (iii) that each has had the
opportunity to be represented by counsel of its own choice in this matter,
including the negotiations which preceded the execution of this Agreement.

          11.18  Agreement to Perform Necessary Acts. Each Party agrees to
                 -----------------------------------
perform any further acts and execute and deliver any and all further documents
and/or instruments which may be

                                     -16-
<PAGE>

reasonably necessary to carry out the provisions of this Agreement and to carry
out the business purposes of Corporation.

          IN WITNESS WHEREOF, Amgen and the Company have caused this Agreement
to be executed by their duly authorized representatives in the manner legally
binding on them as of the date first above written.

                                   KIRIN-AMGEN, INC., a California
                                   corporation

                                   By   /s/ Shinkichi Kubo
                                        ------------------------------
                                        Shinkichi Kubo, Chairman

                                                             "Company"

                                   AMGEN, a California corporation

                                   By   /s/ George B. Rathmann
                                        ------------------------------
                                        George B. Rathmann, President

                                                               "Amgen"

                                     -17-
<PAGE>

                                                                       Exhibit B

                                                                  EXECUTION COPY
                                                                  --------------

                      __________________________________

                               LICENSE AGREEMENT

                                by and between

                              KIRIN-AMGEN, INC.,
                           a California corporation

                                      and

                           KIRIN BREWERY CO., LTD.,
                            a Japanese corporation

                      __________________________________
<PAGE>

                               TABLE OF CONTENTS
                               -----------------

<TABLE>
<CAPTION>
                                                                                                       Page
                                                                                                       ----
<S>                                                                                                    <C>
RECITALS............................................................................................     1

I.       DEFINITIONS

         1.01  Incorporation by Reference...........................................................     2
         1.02  Diagnostic Rights Field of Activity/Diagnostic Rights Technology.....................     2
         1.03  Territory............................................................................     2
         1.04  Party................................................................................     2
         1.05  Subsidiary...........................................................................     2

II.      GRANT OF LICENSE...........................................................................     3

         2.01  Grant of License.....................................................................     3
         2.02  Rights to Sublicense.................................................................     3
         2.03  Amgen License........................................................................     4
         2.04  Other Licenses.......................................................................     4
         2.05  No License Fee.......................................................................     4

III.     DISCLOSURE.................................................................................     5

         3.01  Disclosure...........................................................................     5
         3.02  Confidentiality......................................................................     5

IV.      PATENT APPLICATIONS AND COPYRIGHT REGISTRATIONS............................................     7

         4.01  Patent Applications..................................................................     7

V.       PATENT, COPYRIGHT AND TRADE SECRET ENFORCEMENT.............................................     8

         5.01  Enforcement..........................................................................     8
         5.02  Infringements........................................................................     8
         5.03  Maintenance of Action................................................................     9

VI.      TERM AND TERMINATION.......................................................................    11

         6.01  Term.................................................................................    11
         6.02  Effective Date.......................................................................    11
         6.03  Default..............................................................................    11
         6.04  Survival.............................................................................    12
</TABLE>

                                      -i-
<PAGE>

                                TABLE OF CONTENTS
                                -----------------
                                   (Continued)

<TABLE>
<CAPTION>
                                                                                                         Page
                                                                                                         ----
<S>                                                                                                      <C>
VII.     INFRINGEMENTS................................................................................    13

         7.01  Infringements..........................................................................    13

VIII.    CONSENTS AND APPROVALS.......................................................................    13

         8.01  Best Efforts...........................................................................    13

IX.      NOTICE.......................................................................................    13

         9.01  Notices................................................................................    13

X.       MISCELLANEOUS................................................................................    15

         10.01 Entire Agreement.......................................................................    15
         10.02 Readings...............................................................................    15
         10.03 Execution in Counterparts..............................................................    15
         10.04 Force Majeure..........................................................................    16
         10.05 Applicable Law.........................................................................    16
         10.06 Assignment on Written Consent..........................................................    16
         10.07 Severability...........................................................................    16
         10.08 No Waiver..............................................................................    17
         10.09 Trademarks and Tradenames..............................................................    17
         10.10 Indemnity..............................................................................    17
         10.11 Other Agreements.......................................................................    18
         10.12 Remedies...............................................................................    18
         10.13 Attorneys' Fees and Costs..............................................................    18
         10.14 Number and Gender......................................................................    19
         10.15 Agreement to Perform Necessary Acts....................................................    19
         10.16 Representations........................................................................    19
</TABLE>

                                     -ii-
<PAGE>

                   KIRIN BREWERY CO., LTD./KIRIN-AMGEN, INC.
                   -----------------------------------------
                               LICENSE AGREEMENT
                               -----------------

          THIS KIRIN BREWERY CO., LTD./KIRIN-AMGEN, INC. LICENSE AGREEMENT
("Agreement") is made and entered into this 4th day of December, 1985, and is
made effective as of the 27th day of June, 1985, by and between KIRIN-AMGEN,
INC., a California corporation ("Company"), and KIRIN BREWERY CO., LTD., a
Japanese corporation ("Kirin").

                                R E C I T A L S
                                - - - - - - - -

          A.   Kirin desires to obtain from the Company a license to the EPO
human (and not nonhuman veterinary) diagnostic and reagent rights (collectively
"Diagnostic Rights") in order to exploit the Diagnostic Rights Field of Activity
in its Territory (as hereinafter defined) and the Company is willing to grant
such a license to Kirin.

          B.   Company has granted a similar license to Amgen, of even date
herewith ("Amgen License"), with respect to the exploitation of the Diagnostic
Rights Field of Activity in the United States of America, its territories and
possessions, on substantially the same terms and conditions contained herein and
for the same purposes described herein.
<PAGE>

          NOW, THEREFORE, in consideration of the mutual covenants expressed
herein and other good and valuable consideration, the parties hereby agree as
follows:

                                   ARTICLE I

                                  DEFINITIONS
                                  -----------

          1.01  Incorporation by Reference. Unless otherwise defined herein,
                --------------------------
capitalized terms as used herein shall have the meanings specified in that
certain Shareholders' Agreement of Company dated May 11, 1984.

          1.02  Diagnostic Rights Field of Activity/Diagnostic Rights
                -----------------------------------------------------
Technology. Diagnostic Rights Field of Activity/Diagnostic Rights Technology
----------
shall mean the areas of development manufacture, production, use and worldwide
commercial sale of EPO human diagnostic and/or reagent products and shall
exclude non-human veterinary purposes.

          1.03  Territory: "Territory" shall mean the territory composed of the
                ---------
country of Japan.

          1.04  Party. "Party" shall mean Kirin or the Company or, when used in
                -----
the plural, Kirin and the Company.

          1.05  Subsidiary: "Subsidiary" shall mean a corporate entity more than
                ----------
50% of the voting stock of which is owned or controlled, directly or indirectly,
by Kirin or the Company.

                                      -2-
<PAGE>

                                  ARTICLE II

                               GRANT OF LICENSE
                               ----------------

          2.01  Grant of License.  For the term of this Agreement and subject to
                ----------------
the reservations contained in Sections 2.02, 2.03 and 2.04 hereof the Company
hereby grants to Kirin a sole and exclusive license to the Diagnostic Rights,
for the limited purposes of engaging in the Diagnostic Rights Field of Activity
as expanded by Amendment No. 1 to the Shareholders' Agreement and solely for use
in the manufacture, use and marketing of the Diagnostic Rights in the Kirin
Territory of Japan.

          2.02  Rights to Sublicense. The Company also grants to Kirin the right
                --------------------
to grant sublicenses within and limited to the scope of the right and license
granted to the Company in Section 2.01 only (a) to any Subsidiary of Kirin, (b)
to customers of Kirin, including marketing and distribution agents, in
connection with sales of EPO human diagnostic and reagent products, (c) to a
single manufacturer of such diagnostics and reagents, other than Kirin or any
subsidiary, for the account of Kirin, and (d) to licensees of Kirin under
patents, know-how or materials owned by Kirin to the extent such licensees
require any such sublicenses in order to practice the patents or know-how or to
use the materials that are the subject of the

                                      -3-
<PAGE>

license from Kirin; provided, however, that no sublicense shall be granted under
clause (c) or (d) hereof without the prior written consent (which consent is not
to be unreasonably withheld) of the Company. Any sublicensees of Kirin shall
undertake in writing to be bound by the provisions of Section 3.02 hereof to the
same extent Kirin is bound. Kirin shall notify the Company of the identity of
each sublicensee to whom a sublicense is granted and provide the Company a true
copy of such sublicense. In the event that the license granted to Kirin
hereunder is terminated at any time in accordance with Article VI, and the
Company shall not be in default under Section 6.02 hereof, the Company shall
have the option to terminate or to have Kirin assign to the Company, retroactive
to the date of such termination, any sublicenses granted hereunder by Kirin to
any Subsidiary of Kirin. Kirin shall include, in all its sublicenses granted
hereunder to any Subsidiary of Kirin, provisions for such termination and
assignment.

          2.03  Amgen License. The Company reserves the right to grant a license
                -------------
to utilize the Diagnostic Rights to Amgen in accordance with the terms of the
Amgen License.
          2.04  Other Licenses. The Company reserves the right to grant licenses
                --------------
to utilize the Diagnostic Rights in a similar manner as provided for EPO in the
Shareholders' Agreement.

                                      -4-
<PAGE>

          2.05  License or Royalty Fee. There shall be a one time Two Hundred
                ----------------------
Thousand Dollars (U.S. $200,000.00) fully paid up license fee paid to the
Company by Kirin for the grant of the license described in this Article II, but
there shall be no royalties payable hereunder whatsoever.

                                  ARTICLE III

                                  DISCLOSURE
                                  ----------

          3.01  Disclosure.
                ----------

                (a)  The Company shall reasonably disclose and deliver to Kirin
all Diagnostic Rights Technology in sufficient detail to permit Kirin to employ
such data for the purposes provided herein.

                (b)  Kirin shall have the right to attend and participate in the
Company's technical meetings, conduct plant visits at reasonable intervals and
receive information concerning the Diagnostic Rights Technology. Kirin shall be
provided with reasonable notice of the time and place of such meetings.

          3.02  Confidentiality.
                ---------------

                (a)  Any secret or confidential Diagnostic Rights Technology
which is disclosed to Kirin pursuant to this

                                      -5-
<PAGE>

Agreement or the Shareholders' Agreement, shall be designated as confidential
information in the following manner:

                     (i)   If the disclosure is in written form, by prominently
marking or stamping each document containing such information with a notice
indicating the confidential and proprietary nature of the information; and

                     (ii)  If the disclosure is in oral form, by orally stating
at the time of such disclosure that the information disclosed is confidential
and proprietary and by delivering to Kirin within fifteen (15) days of the oral
disclosure written notice confirming the confidential and proprietary nature of
the information.

                (b)  Except to the extent expressly authorized by this
Agreement, the Shareholders' Agreement, or by other prior written consent of the
Company for the term of this Agreement and thereafter, Kirin shall keep
completely confidential and shall not publish or otherwise disclose to others
and shall not use any secret or confidential Diagnostic Rights Technology
disclosed or provided to Kirin by the Company. For the purposes of this
Agreement, Diagnostic Rights Technology shall be deemed not secret or
confidential to the extent, and only to the extent, that it:

                                      -6-
<PAGE>

                     (i)    was known to Kirin at the time of its disclosure and
not otherwise subject to an obligation of Kirin to keep such information
confidential;

                     (ii)   was generally available to the public or was
otherwise part of the public domain at the time of its disclosure;

                     (iii)  became generally available to the public or became
otherwise part of the public domain after its disclosure and other than through
any act or omission of Kirin in breach of this Agreement; or

                     (iv)   became known to Kirin after its disclosure (A) from
a source other than the Company (including from independent development by
Kirin), (B) other than from a third party who had an obligation to the Company
not to disclose such information to others, and (C) other than under an
obligation of confidentiality. Kirin may disclose any Diagnostic Rights
Technology to the extent such disclosure or delivery is necessary for Kirin to
comply with laws or regulations, or to make, use or sell under any license
granted hereunder by the Company or to sublicense others to do so; provided,
that Kirin shall give the Company reasonable advance notice of such proposed
disclosure or delivery, shall use its best efforts to secure confidential
treatment of the Diagnostic Rights

                                      -7-
<PAGE>

Technology to be disclosed and shall advise the Company in writing of the manner
in which that was done.

                (c)  The obligation of confidentiality imposed by this Section
3.02 shall survive termination of this Agreement for any reason whatsoever.

                                  ARTICLE IV

                PATENT APPLICATIONS AND COPYRIGHT REGISTRATIONS
                -----------------------------------------------

          4.01  Patent Applications. Kirin shall pay the Company's reasonable
                -------------------
costs and expenses (including attorney's fees) incurred to file, prosecute and
maintain in force any patent applications or patents of the Diagnostic Rights
Technology, which Kirin shall desire the Company to file, prosecute or maintain
in the Territory; provided, that, to the extent an application or patent
includes subject matter not covering the manufacture, use and sale of products
in the Diagnostic Rights Field of Activity, Kirin shall pay an equitable pro
rata share of such expenses.

                                   ARTICLE V

                PATENT, COPYRIGHT AND TRADE SECRET ENFORCEMENT
                ----------------------------------------------

          5.01  Enforcement. Subject to Section 5.03, Kirin shall have the
                -----------
right, but not the obligation, to bring, defend and

                                      -8-
<PAGE>

maintain any appropriate suit or action involving infringement of any patent or
copyright, misappropriation of any trade secret or interference with any other
intellectual property right relating to the Diagnostic Rights Technology that
Kirin shall have obtained pursuant to this Agreement.

          5.02  Infringements. Subject to Section 5.03, Kirin shall have the
                -------------
right, but not the obligation, to bring, defend and maintain any appropriate
suit or action involving infringement in the Diagnostic Rights Field of Activity
of any patent of the Diagnostic Rights Technology covering only the making, use
or sale or products or the use of processes in the Diagnostic Rights Field of
Activity. If Kirin finds it necessary to join the Company in such suit or
action, the Company shall execute all papers and perform such other acts as may
be reasonably required and may, at its option, be represented by counsel of its
choice.  Kirin shall pay to the Company its reasonable expenses (excluding its
attorney's fees) in connection with any such suit or action. Should Kirin lack
standing to bring any such action then Kirin may cause the Company to do so upon
first undertaking to indemnify and hold the Company harmless (to the extent
permissible by law) from all consequent liability and to promptly reimburse all
reasonable expenses (including attorney fees) stemming therefrom.  Any amount
recovered in any such

                                      -9-
<PAGE>

action or suit, whether by judgment or settlement, shall be paid to or retained
entirely by Kirin.

          5.03  Maintenance of Action. Kirin shall notify the Company of any
                ---------------------
material infringement in the Diagnostic Rights Field of Activity of any patent
within the Diagnostic Rights Technology covering the making, use or sale of
products or the use of processes both within and outside the Diagnostic Rights
Field of Activity and shall provide the Company with any available evidence of
such infringement. The Company and Kirin shall consult with each other as to the
best manner in which to proceed. The Company shall have the first right, but no
obligation, to bring or defend any suit or action on any claim involving such
infringement of any such patent of the Diagnostic Rights Technology on such
terms relating to reimbursement of associated costs and expenses as shall be
agreed to.  If the Company finds it necessary or desirable to join Kirin in such
suit or action, Kirin shall execute all papers and perform such other acts as
may be reasonably required to do so and may, at its option be represented by
counsel of its choice unless the Company and Kirin otherwise agree, any amount
recovered in any such action, whether by judgment or settlement, after payment
to the Company of such reasonable costs and expenses (excluding attorney's
fees), shall be paid to or retained by Kirin. In the event the

                                     -10-
<PAGE>

Company fails to take action with respect to such infringement within a
reasonable period, no less than six (6) months, following receipt of such notice
and evidence, Kirin shall have the right to bring, defend and maintain any
appropriate suit or action involving such infringement in the Diagnostic Rights
Field of Activity. If Kirin finds it necessary to join the Company in such suit
or action, the Company shall execute all papers and perform such other acts as
may be reasonably required and may, at its option, be represented by counsel of
its choice. Kirin shall pay to the Company the reasonable expenses of the
Company (excluding its attorney's fees) in connection with any such suit or
action. Any amount recovered in any such action or suit, whether by judgment or
settlement, after payment to the Company of such reasonable costs and expenses
(excluding attorney's fees), shall be paid to or retained entirely by Kirin.

                                  ARTICLE VI

                             TERM AND TERMINATION
                             --------------------

          6.01. Term. Unless sooner terminated as provided below, the license
                ----
and rights granted under Sections 2.01 and 2.02 hereof under patents shall
continue with respect to each

                                     -11-
<PAGE>

patent of the Diagnostic Rights Technology for the life of that patent.

          6.02.  Effective Date. This Agreement (including the license and
                 --------------
rights granted under Sections 2.01 and 2.02 hereof) shall come into effect as of
June 27, 1985 and shall remain in full force and effect until the earlier of (a)
the liquidation or dissolution of the Company other than in connection with a
continuation of the business of the Company in some other legal form, or (b)
termination pursuant to either Section 6.03 or 6.04.

          6.03.  Default. In the event that a Party (the "Defaulting Party")
                 -------
shall (a) fail to make any payment hereunder when and as due, or otherwise
default in its obligations hereunder and fail to remedy such default within
sixty (60) days after such default shall have been called to its attention by
notice from another Party, (b) become bankrupt or insolvent, or file a petition
in bankruptcy or make a general assignment for the benefit of creditors or
otherwise acknowledge insolvency, or be adjudged bankruptcy, (c) go or be placed
in a process of complete liquidation other than in connection with a
continuation of the business of the Company in come other legal form, or (d)
suffer the appointment of a receiver for any substantial portion of its business
who shall not be discharged

                                     -12-
<PAGE>

within sixty (60) days after his appointment, then, and in any such event, any
other Party, at its option, may terminate its obligations to and the rights of
the Defaulting Party under this Agreement upon ten (10) day's written notice to
the Defaulting Party, which termination shall be effective as of the occurrence
of the event giving rise to the option to terminate.

          6.04. Survival.  Notwithstanding the termination of a Party's
                --------
obligations to or the rights of the Defaulting Party under this Agreement in
accordance with the provisions of Sections 6.02, 6.03, the provisions of Section
3.02, this Section 6.04 and Article VII hereof shall survive such termination
and continue in full force and effect for an indefinite term.  Upon termination
of this Agreement for any reason, and without limitation of other remedies,
Kirin shall immediately return to the Company (to the extent such return is
technically feasible) all Diagnostic Rights Technology in the possession of
Kirin or its Subsidiaries, or of which Amgen shall have the right to regain
possession or, at the sole election of the Company, shall destroy such
Diagnostic Rights Technology (to the extent technically feasible).

                                     -13-
<PAGE>

                                  ARTICLE VII

                                 INFRINGEMENTS
                                 -------------

          7.01  Infringements. In the event that Kirin is charged with
                -------------
infringement or unauthorized use of the alleged patent rights or proprietary
rights of others by reason of the exploitation by Kirin of Diagnostic Rights
Technology or any component thereof, then the Company shall indemnify and hold
Kirin harmless from such claim to the full extent of any damage recovery with
respect to such claim and legal costs incurred in Kirin's defense.

                                  ARTICLE VIII

                             CONSENTS AND APPROVALS
                             ----------------------

          8.01. Best Efforts. The parties hereto shall use their best efforts to
                ------------
obtain as soon as practicable any and all consents, approvals, orders or
authorizations required to be obtained from any governmental authority with
respect to the provisions hereof.

                                  ARTICLE IX

                                    NOTICE
                                    ------

          9.01. Notices. All notices, requests, demands and other communications
                -------
required or permitted to be given under this

                                     -14-
<PAGE>

Agreement shall be in writing and shall be mailed to the Party to whom notice is
to be given, by telex or facsimile, and confirmed by first class mail,
registered or certified, return receipt requested, postage prepaid, and properly
addressed as follows (in which case such notice shall be deemed to have been
duly given on the third (3rd) day following the date of such sending):

     "Kirin"             Kirin Brewery Company, Limited
                         26-1, Jingumae 6-Chome
                         Shibuya-Ku, Tokyo 150
                         Japan
                         Telex No. 242-5401 Kirin B J
                         Attn: General Manager of R&D Department

     With a copy to:     Musick, Peeler & Garrett
                         One Wilshire Boulevard
                         Suite 2000
                         Los Angeles, CA 90017
                         U.S.A.
                         Telex No. 701357 (MPG LAW UD)
                         Attn: Joel S. Marcus, Esq.

     "Company"           Kirin-Amgen, Inc.
                         1900 Oak Terrace Lane
                         Thousand Oaks, CA 91320
                         U.S.A.
                         Telex No. 4994440 (AMGEN)
                         Attn: Corporate Secretary

     With a copy to:     Musick, Peeler & Garrett
                         One Wilshire Boulevard
                         Suite 2000
                         Los Angeles, CA 90017
                         U.S.A.
                         Telex No. 701357 (MPG LAW UD)
                         Attn: Joel S. Marcus, Esq.

                                     -15-
<PAGE>

Any Party by giving notice to the others in the manner provided above may change
such Party's address for purposes of this Paragraph 9.01.

                                   ARTICLE X

                                 MISCELLANEOUS
                                 -------------

          10.01.  Entire Agreement. This Agreement, together with the other
                  ----------------
written agreements between the parties hereto which are referenced in the
Shareholders' Agreement and Amendment No. 1 thereto, set forth the entire
agreement of the parties with respect to the subject matter hereof and may not
be modified except by a writing signed by authorized representatives of the
parties hereto. To the extent that there may be conflicts or inconsistencies
between the provisions of this Agreement and those contained in the
Shareholders' Agreement, the provisions of the Shareholders' Agreement shall
prevail and govern interpretation.

          10.02.  Headings. Article and section headings in this Agreement are
                  --------
included for convenience of reference only and shall not constitute a part of
this Agreement for any other purpose.

          10.03.  Execution in Counterparts. This Agreement may be executed in
                  -------------------------
any number of counterparts and by different parties hereto in separate
counterparts each of which when so executed

                                     -16-
<PAGE>

and delivered shall be deemed to be an original and all of which counterparts of
this Agreement taken together shall constitute but one and the same instrument.

          10.04.  Force Majeure. It is agreed that each of the Parties hereto is
                  -------------
excused from performing such acts as are required hereunder as may be prevented
by or whose purpose is frustrated by Force Majeure. The Party so affected shall
give notice to the other Party in writing promptly and thereupon shall be
excused from such of its obligations hereunder as it is unable to perform on
account of the Force Majeure throughout the duration thereof plus a period of
thirty (30) days.

          10.05.  Applicable Law. This Agreement shall be governed by and
                  --------------
construed in accordance with the internal laws, and not the law of conflicts, of
the State of California applicable to agreements made and to be performed in
such state.

          10.06.  Assignment on Written Consent. This Agreement shall be binding
                  -----------------------------
upon and inure to the benefit of the Company and Kirin and their respective
successors and assigns to the extent it is assignable. This Agreement may not be
assigned in whole or in part by Kirin, except with the prior written consent of
the Company or except as part of the sale of the Company's entire business
relating to the Field of Activity.

                                     -17-
<PAGE>

          10.07.  Severability. In the event any one or more of the provisions
                  ------------
contained in this Agreement shall be invalid, illegal or unenforceable in any
respect, the validity, legality and/or enforceability of the remaining
provisions contained herein shall not in any way be affected or impaired
thereby. In such event, such invalid provision or provisions shall be validly
reformed to as nearly approximate the intent of the Parties as possible and if
unreformable, shall be severed and deleted from this Agreement.

          10.08.  No Waiver. No failure or delay on the part of either Party in
                  ---------
exercising any right, power or remedy hereunder shall operate as a waiver
thereof; nor shall any single or partial exercise of any such right, power or
remedy preclude any other or further exercise thereof or the exercise of any
other right, power or remedy hereunder or the remedies provided by law.

          10.09.  Trademarks and Tradenames. The Company grants no rights to
                  -------------------------
Kirin in any trademarks or tradenames of the Company or of any of its respective
subsidiaries or affiliated companies.

          10.10.  Indemnity. Kirin hereby (a) releases the Company from any
                  ---------
obligation to defend, indemnify or save Kirin and its agents and employees
harmless from and (b) agrees to defend, indemnify and save the Company harmless
from any and all cost, expenses (including attorneys' fees), liabilities,
damages and

                                     -18-
<PAGE>

claims for any injury or death to persons or damage to or destruction of
property, or other loss, arising out of or in connection with any product made,
used or sold by Kirin or the use by Kirin of the Diagnostic Rights Technology
furnished pursuant to any provision hereunder, or otherwise arising out of or
related to the performance of this Agreement.

          10.11.  Other Agreements. Any other provision of this Agreement
                  ----------------
notwithstanding, noting in this Agreement shall obligate the Company to disclose
to Kirin any information or to make available to the Kirin any materials in
violation of an obligation of secrecy or a limitation of use imposed by a third
party from whom such information or materials shall have been received.

          10.12   Remedies. No right, power or remedy herein conferred upon or
                  --------
reserved to any Party is intended to be exclusive of any other right, power or
remedy or remedies, and each and every right, power and remedy of any Party
pursuant to this Agreement or now or hereafter existing at law or in equity or
by statute or otherwise shall to the extent permitted by law be cumulative and
concurrent, and shall be in addition to every other right, power or remedy
pursuant to this Agreement, or now or hereafter existing at law or in equity or
by statute or otherwise and the exercise or beginning of the exercise by any
Party of any one or more of such rights, powers or remedies shall not preclude

                                     -19-
<PAGE>

the simultaneous or later exercise by any Party of any or all such other rights,
powers or remedies.

          10.13  Attorneys' Fees and Costs. In the event of any action at law or
                 -------------------------
in equity between the Parties hereto to enforce any of the provisions hereof,
the unsuccessful party or parties to such litigation shall pay to the successful
party or parties all costs and expenses, including actual attorneys' fees,
incurred therein by such successful party or parties; and if such successful
party or parties shall recover judgment in any such action or proceeding, such
costs, expenses and attorneys' fees may be included in and as part of such
judgment. The successful party shall be the party who is entitled to recover its
costs of suit, whether or not the suit proceeds to final judgment. A party not
entitled to recover its costs shall not recover attorneys' fees.

          10.14  Number and Gender. Words in the singular shall include the
                 -----------------
plural, and words in a particular gender shall include either or both additional
genders, when the context in which such words are used indicates that such is
the intent.

          10.15  Agreement to Perform Necessary Acts. Each Party agrees to
                 -----------------------------------
perform any further acts and execute and deliver any and all further documents
and/or instruments which may be reasonably necessary to carry out the provisions
of this Agreement.

                                     -20-
<PAGE>

          10.16  Representations. Each of the Parties hereto acknowledges and
                 ---------------
agrees (i) that no representation or promise not expressly contained in this
Agreement has been made by any other Party hereto or by any of its agents,
employees, representatives or attorneys; (ii) that this Agreement is not being
entered into on the basis of, or in reliance on, any promise or representation,
expressed or implied, covering the subject matter hereof, other than those which
are set forth expressly in this Agreement; and (iii) that each has had the
opportunity to be represented by counsel of its own choice in this matter,
including the negotiations which preceded the execution of this Agreement.

          IN WITNESS WHEREOF, the parties have caused this Agreement to be
executed by their duly authorized representatives in the manner legally binding
on them as of the date first above written.

                                    KIRIN BREWERY CO., LTD.,
                                    a Japanese-Corporation

                                    By /s/ Shinkichi Kubo
                                      -------------------
                                     Shinkichi Kubo,
                                     Senior Managing Director
                                                        "Kirin"

                                    KIRIN-AMGEN, INC.,
                                    a California corporation

                                    By /s/ George B. Rathmann
                                      -----------------------
                                     George B. Rathmann, President
                                                       "Company"

                                     -21-
<PAGE>

                                                                       Exhibit C

                                                            EXECUTION COPY
                                                            --------------

                      __________________________________

                               LICENSE AGREEMENT

                                by and between

                              KIRIN-AMGEN, INC.,

                           a California corporation

                                      and

                                    AMGEN,

                           a California corporation

                      __________________________________
<PAGE>

                               TABLE OF CONTENTS
                               -----------------

<TABLE>
<CAPTION>
                                                                                                         Page
                                                                                                         ----
<S>                                                                                                      <C>
RECITALS...............................................................................................    1

I.       DEFINITIONS...................................................................................    2

         1.01  Incorporation by Reference..............................................................    2
         1.02  Diagnostic Rights Field of Activity/Diagnostic Rights Technology........................    2
         1.03  Territory...............................................................................    2
         1.04  Party...................................................................................    2
         1.05  Subsidiary..............................................................................    2

II.      GRANT OF LICENSE..............................................................................    3

         2.01  Grant of License........................................................................    3
         2.02  Rights to Sublicense....................................................................    3
         2.03  Amgen License...........................................................................    4
         2.04  Other Licenses..........................................................................    4
         2.05  No License Fee..........................................................................    4

III.     DISCLOSURE....................................................................................    5

         3.01  Disclosure..............................................................................    5
         3.02  Confidentiality.........................................................................    5

IV.      PATENT APPLICATIONS AND COPYRIGHT REGISTRATIONS...............................................    7

         4.01  Patent Applications.....................................................................    7

V.       PATENT, COPYRIGHT AND TRADE SECRET ENFORCEMENT................................................    8

         5.01  Enforcement.............................................................................    8
         5.02  Infringements...........................................................................    8
         5.03  Maintenance of Action...................................................................    9

VI.      TERM AND TERMINATION:.........................................................................   11

         6.01  Term....................................................................................   11
         6.02  Effective Date..........................................................................   11
         6.03  Default.................................................................................   11
         6.04  Survival................................................................................   12
</TABLE>

                                      -i-
<PAGE>

                               TABLE OF CONTENTS
                               -----------------
                                   Continued

<TABLE>
<CAPTION>
                                                                                                    Page
                                                                                                    ----
<S>                                                                                                 <C>
VII.     INFRINGEMENTS..........................................................................     12

         7.01  Infringements....................................................................     12

VIII.    CONSENTS AND APPROVALS.................................................................     13

         8.01  Best Efforts.....................................................................     13

IX.      NOTICE.................................................................................     13

         9.01  Notices..........................................................................     13

X.       MISCELLANEOUS..........................................................................     15

         10.01 Entire Agreement.................................................................     15
         10.02 Headings.........................................................................     15
         10.03 Execution in Counterparts........................................................     15
         10.04 Force Majeure....................................................................     16
         10.05 Applicable Law...................................................................     16
         10.06 Assignment on Written Consent....................................................     16
         10.07 Severability.....................................................................     16
         10.08 No Waiver........................................................................     17
         10.09 Trademarks and Tradenames........................................................     17
         10.10 Indemnity........................................................................     17
         10.11 Other Agreements.................................................................     18
         10.12 Remedies.........................................................................     18
         10.13 Attorneys' Fees and Costs........................................................     18
         10.14 Number and Gender................................................................     19
         10.15 Agreement to Perform Necessary Acts..............................................     19
         10.16 Representations..................................................................     19
</TABLE>

                                     -ii-
<PAGE>

                                                                       Exhibit B

                            AMGEN/KIRIN-AMGEN, INC.
                            -----------------------

                               LICENSE AGREEMENT
                               -----------------

          THIS AMGEN/KIRIN-AMGEN, INC. LICENSE AGREEMENT is made and entered
into this 4th day of December, 1985, and is made effective as of the 27th day of
June, 1985, by and between KIRIN-AMGEN, INC., a California corporation
("Company"), and AMGEN, a California corporation ("Amgen").

                                R E C I T A L S
                                - - - - - - - -

          A.   Amgen desires to obtain from the Company a license to the EPO
human (and not non-human veterinary) diagnostic and reagent rights (collectively
"Diagnostic Rights") in order to exploit the Diagnostic Rights Field of Activity
in its Territory (as hereinafter defined) and the Company is willing to grant
such a license to Amgen.

          B.   Company has granted a similar license to Kirin, of even date
herewith ("Kirin License"), with respect to the exploitation of the Diagnostic
Rights Field of Activity in Japan, on substantially the same terms and
conditions contained herein and for the same purposes described herein.

          NOW, THEREFORE, in consideration of the mutual covenants expressed
herein and other good and valuable consideration, the parties hereby agree as
follows:

                                      -3-

<PAGE>

                                   ARTICLE I

                                  DEFINITIONS
                                  -----------

          1.01  Incorporation by Reference. Unless otherwise defined herein,
                --------------------------
capitalized terms shall have the meanings specified in that certain
Shareholders' Agreement of Company dated May 11, 1984.

          1.02  Diagnostic Rights Field of Activity/Diagnostic Rights
                -----------------------------------------------------
Technology. Diagnostic Rights Field of Activity/Diagnostic Rights Technology
----------
shall mean the areas of development manufacture, production, use and worldwide
commercial sale of EPO human diagnostic and/or reagent products and shall
exclude nonhuman veterinary purposes.

          1.03  Territory. "Territory" shall mean the territory composed of the
                ---------
United States of America, its territories and possessions.

          1.04  Party. "Party" shall mean Amgen or the Company or, when used in
                -----
the plural, Amgen and the Company.

          1.05  Subsidiary. "Subsidiary" shall mean a corporate entity more than
                ----------
50% of the voting stock of which is owned or controlled, directly or indirectly,
by Amgen or the Company.

                                      -2-
<PAGE>

                                  ARTICLE II

                               GRANT OF LICENSE
                               ----------------

          2.01  Grant of License.  For the term of this Agreement and subject to
                ----------------
the reservations contained in Sections 2.02, 2.03 and 2.04 hereof, the Company
hereby grants to Amgen a sole and exclusive license to the Diagnostic Rights,
for the limited purpose of engaging in the Field of Activity as expanded by
Amendment No. 1 to the Shareholders' Agreement and solely for use in the
manufacture, use and marketing of the Diagnostic Rights in the Amgen Territory.

          2.02  Rights to Sublicense.  The Company also grants to Amgen the
                --------------------
right to grant sublicenses within and limited to the scope of the right and
license granted to the Company in Section 2.01 only (a) to any Subsidiary of
Amgen, (b) to customers of Amgen, including marketing and distribution agents,
in connection with sales of EPO human diagnostic and reagent products, (c) to a
single manufacturer of such diagnostics and reagents, other than Amgen or any
Subsidiary, for the account of Amgen, and (d) to licensees of Amgen under
patents, know-how or materials owned by Amgen to the extent such licensees
require any such sublicense in order to practice the patents or know-how or to
use the materials that are the subject of the license from Amgen; provided,
however, that no sublicense shall be granted under clause (c) or (d) hereof

                                      -3-
<PAGE>

without the prior written consent (which consent is not to be unreasonably
withheld) of the Company. Any sublicensees of Amgen shall undertake in writing
to be bound by the provisions of Section 3.02 hereof to the same extent Amgen is
bound. Amgen shall notify the Company of the identify (if each sublicensee to
whom a sublicense is granted and provide the Company a true copy of such
sublicense. In the event that the license granted to Amgen hereunder is
terminated at any time in accordance with Article VI, and the Company shall not
be in default under Section 6.02, the Company shall have the option to terminate
or to have Amgen assign to the Company, retroactive to the date of such
termination, any sublicenses granted hereunder by Amgen to any Subsidiary of
Amgen. Amgen shall include, in all its sublicenses granted hereunder to any
Subsidiary of Amgen, provisions for such termination and assignment.

          2.03  Kirin License. The Company reserves the right to grant a license
                -------------
to utilize the Diagnostic Rights to Kirin in accordance with the terms of the
Kirin License.

          2.04  Other Licenses. The Company reserves the right to grant licenses
                --------------
to utilize the Diagnostic Rights in a similar manner as provided for EPO in the
Shareholders` Agreement.

          2.05  License or Royalty Fee. There shall be a one time Two Hundred
                ----------------------
Thousand Dollars (U.S. $200,000.00) fully paid

                                      -4-
<PAGE>

up license fee paid to the Company by Amgen for the grant of the license
described in this Article II, but there shall be no royalties payable hereunder
whatsoever.

                                  ARTICLE III

                                  DISCLOSURE
                                  ----------

          3.01  Disclosure.
                ----------
               (a)  The Company shall reasonably disclose and deliver to Amgen
all Diagnostic Rights Technology in sufficient detail to permit Amgen to employ
such data for the purposes provided herein.

               (b)  Amgen shall have the right to attend and participate in the
Company's technical meetings, conduct plant visits at reasonable intervals and
receive information concerning the Diagnostic Rights Technology. Amgen shall be
provided with reasonable notice of the time and place of such meetings.

          3.02 Confidentiality.
               ---------------

               (a) Any secret or confidential Diagnostic Rights Technology
which is disclosed to Amgen pursuant to this Agreement or the Shareholders'
Agreement, shall be designated as confidential information in the following
manner:

                    (i)  If the disclosure is in written form, by prominently
marking or stamping each document containing such

                                      -5-
<PAGE>

information with a notice indicating the confidential and proprietary nature of
the information; and

               (ii) If the disclosure is in oral form, by orally stating at the
time of such disclosure that the information disclosed is confidential and
proprietary and by delivering to Amgen within fifteen (15) days of the oral
disclosure written notice confirming the confidential and proprietary nature of
the information.

               (b)  Except to the extent expressly authorized by this Agreement,
the Shareholders' Agreement, or by other prior written consent of the Company
for the term of this Agreement and thereafter, Amgen shall keep completely
confidential and shall not publish or otherwise disclose to others and shall not
use any secret or confidential Diagnostic Rights Technology disclosed or
provided to Amgen by the Company. For the purposes of this Agreement, Diagnostic
Rights Technology shall be deemed not secret or confidential to the extent, and
only to the extent, that it:

               (i)  was known to Amgen at the time of its disclosure and not
     otherwise subject to an obligation of Amgen to keep such information
     confidential;

               (ii) was generally available to the public or was otherwise part
     of the public domain at the time of its disclosure;

                                      -6-
<PAGE>

               (iii)  became generally available to the public or became
     otherwise part of the public domain after its disclosure and other than
     through any act or omission of Amgen in breach of this Agreements; or

               (iv)   became known to Amgen after its disclosure (A) from a
     source other than the Company (including from independent development by
     Amgen), (B) other than from a third party who had an obligation to the
     Company not to disclose such information to others, and (C) other than
     under an obligation of confidentiality.

Amgen may disclose any Diagnostic Rights Technology to the extent such
disclosure or delivery is necessary for Amgen to comply with laws or
regulations, or to make, use or sell under any license granted hereunder by the
Company or to sublicense others to do so; provided, that Amgen shall give the
Company reasonable advance notice of such proposed disclosure or delivery, shall
use its best efforts to secure confidential treatment of the Diagnostic Rights
Technology to be disclosed and shall advise the Company in writing of the manner
in which that was done.

               (c)    The obligation of confidentiality imposed by this Section
3.02 shall survive termination of this Agreement for any reason whatsoever.

                                      -7-
<PAGE>

                                  ARTICLE IV

                PATENT APPLICATIONS AND COPYRIGHT REGISTRATIONS
                -----------------------------------------------

          4.01  Patent Applications.  Amgen shall pay the Company's reasonable
                -------------------
costs and expenses (including attorney's fees) incurred to file, prosecute and
maintain in force any patent applications or patents of the Diagnostic Rights
Technology which Amgen shall desire the Company to file, prosecute or maintain
in the Territory; provided, that, to the extent an application or patent
includes subject matter not covering the manufacture, use and sale of products
in the Diagnostic Rights Field of Activity, Amgen shall pay an equitable pro
rata share of such expenses.

                                   ARTICLE V

                 PATENT, COPYRIGHT AND TRADE SECRET ENFORCEMENT
                 ----------------------------------------------

          5.01  Enforcement.  Subject to Section 5.03, Amgen shall have the
                -----------
right, but not the obligation, to bring, defend and maintain any appropriate
suit or action involving infringement of any patent or copyright,
misappropriation of any trade secret or interference with any other intellectual
property right relating to the Diagnostic Rights Technology that Amgen shall
have obtained pursuant to this Agreement.

          5.02  Infringements.  Subject to Section 5.03, Amgen shall have the
                -------------
right, but not the obligation, to bring, defend

                                     - 8 -
<PAGE>

and maintain any appropriate suit or action involving infringement in the
Diagnostic Rights Field of Activity of any patent of the Diagnostic Rights
Technology covering only the making, use or sale of products or the use of
processes in the Diagnostic Rights Field of Activity. If Amgen finds it
necessary to join the Company in such suit or action, the Company shall execute
all papers and perform such other acts as may be reasonably required and may, at
its option, be represented by counsel of its choice. Amgen shall pay to the
Company its reasonable expenses (excluding its attorney's fees) in connection
with any such suit or action. Should Amgen lack standing to bring any such
action then Amgen may cause the Company to do so upon first undertaking to
indemnify and hold the Company harmless (to the extent permissible by law) from
all consequent liability and to promptly reimburse all reasonable expenses
(including attorney fees) stemming therefrom. Any amount recovered in any such
action or suit, whether by judgment or settlement, shall be paid to or retained
entirely by Amgen.

          5.03  Maintenance of Action.  Amgen shall notify the Company of any
                ---------------------
material infringement in the Diagnostic Rights Field of Activity of any patent
within the Diagnostic Rights Technology covering the making, use or sale of
products or the use of processes both within and outside the Diagnostic Rights

                                     - 9 -
<PAGE>

Field of Activity and shall provide the Company with any available evidence of
such infringement. The Company and Amgen shall consult with each other as to the
best manner in which to proceed. The Company shall have the first right, but no
obligation, to bring or defend any suit or action on any claim involving such
infringement of any such patent of the Diagnostic Rights Technology on such
terms relating to reimbursement of associated costs and expenses as shall be
agreed to. If the Company finds it necessary or desirable to join Amgen in such
suit or action, Amgen shall execute all papers and perform such other acts as
may be reasonably required to do so and may, at its option be represented by
counsel of its choice unless the Company and Amgen otherwise agree, any amount
recovered in any such action, whether by judgment or settlement, after payment
to the Company of such reasonable costs and expenses (excluding attorney's
fees), shall be paid to or retained by Amgen. In the event the Company fails to
take action with respect to such infringement within a reasonable period, no
less than six (6) months, following receipt of such notice and evidence, Amgen
shall have the right to bring, defend and maintain any appropriate suit or
action involving such infringement in the Diagnostic Rights Field of Activity.
If Amgen finds it necessary to join the Company in such suit or action, the
Company shall execute all papers and

                                    - 10 -
<PAGE>

perform such other acts as may be reasonably required and may, at its option, be
represented by counsel of its choice. Amgen shall pay to the Company the
reasonable expenses of the Company (excluding it attorney's fees) in connection
with any such suit or action. Any amount recovered in any such action or suit,
whether by judgment or settlement, after payment to the Company of such
reasonable costs and expenses (excluding attorney's fees), shall be paid to or
retained entirely by Amgen.

                                  ARTICLE VI

                             TERM AND TERMINATION
                             --------------------

          6.01  Term.  Unless sooner terminated as provided below, the license
                ----
and rights granted under Sections 2.01 and 2.02 hereof under patents shall
continue with respect to each patent of the Diagnostic Rights Technology for the
life of that patent.

          6.02  Effective Date.  This Agreement (including the license and
                --------------
rights granted under Sections 2.01 and 2.02 hereof) shall come into effect as of
June 27, 1985 and shall remain in full force and effect until the earlier of (a)
the liquidation or dissolution of the Company other than in connection with a
continuation of the business of the Company in some other legal form, or (b)
termination pursuant to either Section 6.03 or 6.04.

                                    - 11 -
<PAGE>

          6.03  Default.  In the event that a Party (the "Defaulting Party")
                -------
shall (a) fail to make any payment hereunder when and as due, or otherwise
default in its obligations hereunder and fail to remedy such default within
sixty (60) days after such default shall have been called to its attention by
notice from another Party, (b) become bankrupt or insolvent, or file a petition
in bankruptcy or make a general assignment for the benefit of creditors or
otherwise acknowledge insolvency, or be adjudged bankruptcy, (c) go or be placed
in a process of complete liquidation other than in connection with a
continuation of the business of the Company in some other legal form, or (d)
suffer the appointment of a receiver for any substantial portion of its business
who shall not be discharged within sixty (60) days after his appointment, then,
and in any such event, any other Party, at its option, may terminate its
obligations to and the rights of the Defaulting Party under this Agreement upon
ten (10) days' written notice to the Defaulting Party, which termination shall
be effective as of the occurrence of the event giving rise to the option to
terminate.

          6.04  Survival.  Notwithstanding the termination of a Party's
                --------
obligations to or the rights of the Defaulting Party under this Agreement in
accordance with the provisions of Sections 6.02, 6.03, the provisions of Section
3.02, this Section 6.04 and

                                    - 12 -
<PAGE>

Article VII hereof shall survive such termination and continue in full force and
effect for an indefinite term. Upon termination of this Agreement for any
reason, and without limitation of other remedies, Amgen shall immediately return
to the Company (to the extent such return is technically feasible) all
Diagnostic Rights Technology in the possession of Amgen or its Subsidiaries, or
of which Amgen shall have the right to regain possession or, at the sole
election of the Company, shall destroy such Diagnostic Rights Technology (to the
extent technically feasible).

                                  ARTICLE VII

                                 INFRINGEMENTS
                                 -------------

          7.01  Infringements.  In the event that Amgen is charged with
                -------------
infringement or unauthorized use of the alleged patent rights or proprietary
rights of others by reason of the exploitation by Amgen of Diagnostic Rights
Technology or any component thereof, then the Company shall indemnify and hold
Amgen harmless from such claim to the full extent of any damage recovery with
respect to such claim and legal costs incurred in Amgen's defense.

                                    - 13 -
<PAGE>

                                 ARTICLE VIII

                            CONSENTS AND APPROVALS
                            ----------------------

          8.01  Best Efforts.  The parties hereto shall use their best efforts
                ------------
to obtain as soon as practicable any and all consents, approvals, orders or
authorizations required to be obtained from any governmental authority with
respect to the provisions hereof.

                                  ARTICLE IX

                                    NOTICE
                                    ------

          9.01  Notices.  All notices, requests, demands and other
                -------
communications required or permitted to be given under this Agreement shall be
in writing and shall be mailed to the Party to whom notice is to be given, by
telex or facsimile, and confirmed by first class mail, registered or certified,
return receipt requested, postage prepaid, and properly addressed as follows (in
which case such notice shall be deemed to have been duly given on the third
(3rd) day following the date of such sending):

                                    - 14 -
<PAGE>

     "Amgen"            Amgen
                        1900 Oak Terrace Lane
                        Thousand Oaks, CA 91320
                        U.S.A.
                        Telex No. 499-9315 (AMGEN)
                        Attn: Corporate Secretary

     With a copy to:    Cooley, Godward, Castro,
                          Huddleson & Tatum
                        One Maritime Plaza, 20th Floor
                        San Francisco, CA 94111
                        U.S.A.
                        Telex No. 910-372-7370 Cooley SFO
                        Attn: Alan C. Mendelson, Esq.

     "Company"          Kirin-Amgen, Inc.
                        1900 Oak Terrace Lane
                        Thousand Oaks, CA 91320
                        U.S.A.
                        Telex No. 4994440 (AMGEN)
                        Attn: Corporate Secretary

     With a copy to:    Musick, Peeler & Garrett
                        One Wilshire Boulevard
                        Suite 2000
                        Los Angeles, CA 90017
                        U.S.A.
                        Telex No. 701357 (MPG LAW UD)
                        Attn: Joel S. Marcus, Esq.

Any Party by giving notice to the others in the manner provided above may change
such Party's address for purposes of this Paragraph 9.01.

                                   ARTICLE X

                                 MISCELLANEOUS
                                 -------------

          10.01  Entire Agreement.  This Agreement, together with the other
                 ----------------
written agreements between the parties hereto which are referenced in the
Shareholders' Agreement and Amendment No. 1

                                    - 15 -
<PAGE>

thereto, set forth the entire agreement of the parties with respect to the
subject matter hereof and may not be modified except by a writing signed by
authorized representatives of the parties hereto. To the extent that there may
be conflicts or inconsistencies between the provisions of this Agreement and
those contained in the Shareholders' Agreement, the provisions of the
Shareholders' Agreement shall prevail and govern interpretation.

          10.02  Headings.  Article and section headings in this Agreement are
                 --------
included for convenience of reference only and shall not constitute a part of
this Agreement for any other purpose.

          10.03  Execution in Counterparts.  This Agreement may be executed in
                 -------------------------
any number of counterparts and by different parties hereto in separate
counterparts each of which when so executed and delivered shall be deemed to be
an original and all of which counterparts of this Agreement taken together shall
constitute but one and the same instrument.

          10.04  Force Majeure.  It is agreed that each of the Parties hereto is
                 -------------
excused from performing such acts as are required hereunder as may be prevented
by or whose purpose is frustrated by Force Majeure. The Party so affected shall
give notice to the other Party in writing promptly and thereupon shall be
excused from such of its obligations hereunder as it is unable

                                    -16-
<PAGE>

to perform on account of the Force Majeure throughout the duration thereof plus
a period of thirty (30) days.

          10.05  Applicable Law.  This Agreement shall be governed by and
                 --------------
construed in accordance with the internal laws, and not the law of conflicts, of
the State of California applicable to agreements made and to be performed in
such state.

          10.06  Assignment on Written Consent.  This Agreement shall be binding
                 -----------------------------
upon and inure to the benefit of the Company and Amgen and their respective
successors and assigns to the extent it is assignable. This Agreement may not be
assigned in whole or in part by Amgen, except with the prior written consent of
the Company or except as part of the sale of the Company's entire business
relating to the Field of Activity.

          10.07  Severability.  In the event any one or more of the provisions
                 ------------
contained in this Agreement shall be invalid, illegal or unenforceable in any
respect, the validity, legality and/or enforceability of the remaining
provisions contained herein shall not in any way be affected or impaired
thereby. In such event, such invalid provision or provisions shall be validly
reformed to as nearly approximate the intent of the Parties as possible and if
unreformable, shall be severed and deleted from this Agreement.

                                    -17-
<PAGE>

          10.08  No Waiver.  No failure or delay on the part of either Party in
                 ---------
exercising any right, power or remedy hereunder shall operate as a waiver
thereof; nor shall any single or partial exercise of any such right, power or
remedy preclude any other or further exercise thereof or the exercise of any
other right, power or remedy hereunder or the remedies provided by law.

          10.09  Trademarks and Tradenames.  The Company grants no rights to
                 -------------------------
Amgen in any trademarks or tradenames of the Company or of any of its respective
subsidiaries or affiliated companies.

          10.10  Indemnity.  Amgen hereby (a) releases the Company from any
                 ---------
obligation to defend indemnify or save Amgen and its agents and employees
harmless from and (b) agrees to defend, indemnify and save the Company harmless
from any and all cost, expenses (including attorneys' fees), liabilities,
damages and claims for any injury or death to persons or damage to or
destruction of property, or other loss, arising out of or in connection with any
product made, used or sold by Amgen or the use by Amgen of any Diagnostic Rights
Technology furnished pursuant to any provision hereunder, or otherwise arising
out of or related to the performance of this Agreement.

          10.11  Other Agreements.  Any other provision of this Agreement
                 ----------------
notwithstanding, nothing in this Agreement shall

                                    -18-
<PAGE>

obligate the Company to disclose to Amgen any information or to make available
to the Amgen any materials in violation of an obligation of secrecy or a
limitation of use imposed by a third party from whom such information or
materials shall have been received.

          10.12  Remedies.  No right, power or remedy herein conferred upon or
                 --------
reserved to any Party is intended to be exclusive of any other right, power or
remedy or remedies, and each and every right, power and remedy of any Party
pursuant to this Agreement or now or hereafter existing at law or in equity or
by statute or otherwise shall to the extent permitted by law be cumulative and
concurrent, and shall be in addition to every other right, power or remedy
pursuant to this Agreement, or now or hereafter existing at law or in equity or
by statute or otherwise and the exercise or beginning of the exercise by any
Party of any one or more of such rights, powers or remedies shall not preclude
the simultaneous or later exercise by any Party of any or all such other rights,
powers or remedies.

          10.13  Attorneys' Fees and Costs.  In the event of any action at law
                 -------------------------
or in equity between the Parties hereto to enforce any of the provisions hereof,
the unsuccessful party or parties to such litigation shall pay to the successful
party or parties all costs and expenses, including actual attorneys' fees,
incurred therein by such successful party or parties; and

                                    -19-
<PAGE>

if such successful party or parties shall recover judgment in any such action or
proceeding, such costs, expenses and attorneys' fees may be included in and as
part of such judgment. The successful party shall be the party who is entitled
to recover its costs of suit, whether or not the suit proceeds to final
judgment. A party not entitled to recover its costs shall not recover attorneys'
fees.

          10.14  Number and Gender.  Words in the singular shall include the
                 -----------------
plural, and words in a particular gender, shall include either or both
additional genders, when the context in which such words are used indicates that
such is the intent.

          10.15  Agreement to Perform Necessary Acts.  Each Party agrees to
                 -----------------------------------
perform any further acts and execute and deliver any and all further documents
and/or instruments which may be reasonably necessary to carry out the provisions
of this Agreement.

          10.16  Representations.  Each of the Parties hereto acknowledges and
                 ---------------
agrees (i) that no representation or promise not expressly contained in this
Agreement has been made by any other Party hereto or by any of its agents,
employees, representatives or attorneys; (ii) that this Agreement is not being
entered into on the basis of, or in reliance on, any promise or representation,
expressed or implied, covering the

                                    -20-
<PAGE>

subject matter hereof, other than those which are set forth expressly in this
Agreement; and (iii) that each has had the opportunity to be represented by
counsel of its own choice in this matter, including the negotiations which
preceded the execution of this Agreement.

          IN WITNESS WHEREOF, the parties have caused this Agreement to be
executed by their duly authorized representatives in the manner legally binding
on them as of the date first above written.

                              AMGEN, a California corporation

                              By  /s/George B. Rathmann
                                -----------------------------
                                  George B. Rathmann,
                                  President
                                                   "Amgen"

                              KIRIN-AMGEN, INC.,
                              a California corporation

                              By  /s/Shinkichi Kubo
                                -----------------------------
                                  Shinkichi Kubo,
                                  Chairman
                                                   "Company"

                                    -21-
<PAGE>

                                                                    Exhibit 10.4

                                AMENDMENT NO. 2
                                ---------------
                                       TO
                                       --
                            SHAREHOLDERS' AGREEMENT
                            -----------------------
                                       OF
                                       --
                               KIRIN-AMGEN, INC.
                               -----------------

     THIS AMENDMENT NO. 2 ("Amendment No. 2") TO THAT CERTAIN SHAREHOLDERS'
AGREEMENT OF KIRIN-AMGEN, INC., DATED MAY 11, 1984 is made and entered into this
29th day of July, 1985, and is effective as of the lst day of July, 1985, by and
among KIRIN BREWERY COMPANY, LTD., a Japanese corporation ("Kirin"), AMGEN, a
California corporation ("Amgen"), and KIRIN-AMGEN, INC., a California
corporation ("K-A").

                                 R E C I T A L
                                 -------------

     Pursuant to Paragraph 22.19 of the Shareholders' Agreement regarding
expansion of the business of K-A, Kirin and Amgen desire to expand K-A's
business into the research and development of Thrombopoietin including, without
limitation, any and all rights therein and thereto (collectively, "TPO").

     NOW, THEREFORE, it is agreed as follows:

     1.   TPO: EXPANSION OF CORPORATION'S BUSINESS OPPORTUNITIES
          ------------------------------------------------------

          Kirin and Amgen hereby agree that Paragraph 2.06  of the Shareholders'
Agreement shall be expanded to include the research and development of TPO and
the ultimate production and marketing of TPO.

     2.   TPO RESEARCH AND DEVELOPMENT
          ----------------------------

          Subject only to the conditions of (i) the simultaneous establishment
of the Pluripoietin project by and between Kirin and Amgen, and (ii) the
execution on or before October 31, 1985 by K-A and a third party of a License
Agreement with respect to erythropoietin for human therapeutic uses in certain
territories, K-A shall commence the research and development of TPO. Kirin and
Amgen agree
<PAGE>

that they will fund equally, on a 50-50 basis, the research and development of
TPO until the earlier occurrence of October 31, 1985 or the satisfaction of the
conditions set forth in this paragraph. If the conditions are satisfied on or
before October 31, 1985, then K-A will reimburse Amgen and Kirin for any and all
expenditures made by them regarding the research and development of TPO between
July 1, 1985 and the date of satisfaction of the conditions. If the conditions
have not been satisfied on or before October 31, 1985, then all funding
obligations of Kirin and Amgen shall cease and Kirin and Amgen shall discuss the
continuation and further funding of the research and development of TPO pursuant
to this Amendment No. 2. Amgen and Kirin shall use their best efforts to agree
on such continuation and funding; provided that, if Kirin and Amgen are unable
to reach agreement on or before November 15, 1985, then their obligations
hereunder shall terminate and have no further force and effect as of November
15, 1985.

     3.   CONSISTENCY WITH SHAREHOLDERS' AGREEMENT AND RATIFICATION
          ---------------------------------------------------------

         The rights and obligations of the parties with respect to this
Amendment No. 2 as an additional expansion of K-A's business opportunities are
otherwise consistent with the provisions of the Shareholders' Agreement.  All
other terms and conditions of the Shareholders' Agreement are hereby confirmed
and ratified in all respects.

     4.   FURTHER INSTRUMENTS
          -------------------

          Each party hereto agrees to perform any and all further acts and
execute and deliver any and all further documents and/or instruments which may
be reasonable or necessary to carry out the provisions of this Amendment No. 2
to the Shareholders' Agreement and to carry out this further business purpose of
K-A.
<PAGE>

     IN WITNESS WHEREOF, the undersigned have caused this Amendment No. 2 to be
executed on July 29, 1985 by their duly authorized representatives in the manner
legally binding upon them.

                              KIRIN BREWERY COMPANY, LTD.,
                              a Japanese corporation

                              By  /s/Shinkichi Kubo
                                 ------------------
                                  Shinkichi Kubo,
                                  Senior Managing Director

                                              "Kirin"

                              AMGEN, a California corporation

                              By  /s/George B. Rathmann
                                  ---------------------
                                  George B. Rathmann,
                                  President

                                              "Amgen"
<PAGE>

                              KIRIN-AMGEN, INC.
                              a California corporation

                              BY  /s/Tasuhiko Kaneko
                                  ------------------
                                  ------------------
                                  Its
                                     ---------------
                                              "K-A"
<PAGE>

                                                                    Exhibit 10.4

                                AMENDMENT NO. 3
                                ---------------
                                       TO
                                       --
                            SHAREHOLDERS' AGREEMENT
                            -----------------------
                                       OF
                                       --
                               KIRIN-AMGEN, INC.
                               -----------------

    THIS AMENDMENT NO. 3 TO THAT CERTAIN SHAREHOLDERS' AGREEMENT OF KIRIN-AMGEN,
INC., DATED MAY 11, 1984, as previously amended ("Amendment No. 3"), is made and
entered into this  19th  day of December, 1985 by and among KIRIN BREWERY
                  ------
COMPANY, LTD., a Japanese corporation ("Kirin"), AMGEN, a California corporation
("Amgen"), and KIRIN-AMGEN, INC., a California corporation ("Corporation").

                                R E C I T A L S
                                - - - - - - - -

    A.  Kirin and Amgen mutually agree that their relationship with respect to
EPO has been beneficial to both companies and wish to adopt this Amendment No. 3
to clarify their agreements with respect to TPO and PPO.

    B.  This Amendment No. 3 relates to certain agreements with respect to TPO
(as defined in Amendment No. 2 to the Shareholders' Agreement) and PPO (as
defined in that certain Research, Development, Technology Disclosure and License
Agreement: PPO between Kirin and Amgen) and the manufacture, production and
world-wide commercial sale of TPO and PPO products.

     NOW, THEREFORE, it is agreed as follows:

1.   CERTAIN AGREEMENTS WITH RESPECT TO TPO AND PPO
     ----------------------------------------------

    1.01 It is agreed that Kirin shall have an exclusive license with respect to
TPO and PPO in the territory of Japan and Amgen shall have an exclusive license
with respect to TPO and PPO in the territory of the United States. The initial
royalty rate, which is subject to adjustment as set forth below, shall be 5% of
net sales of TPO and/or PPO products from each Kirin and Amgen to Corporation.

    1.02 The parties agree that the initial royalty rate established in
Paragraph 1.01 above may be subject to adjustment when TPO and/or PPO are
further along in their development and/or marketing stage. Only at such time
will the parties be able to more fully understand the potential market and
economic implications of the initial royalty rate established herein.
<PAGE>

     1.03 The parties agree that the final royalty rate to be mutually agreed
upon and embodied in definitive license agreements among the parties may involve
a maximum royalty rate of five percent (5%) down to zero (0). The parties may
agree upon different royalty rates (e.g. Kirin 3%; Amgen 5%), the same royalty
rate (but different than the initial royalty rate), or the initial royalty rate
may remain unchanged.

2.   THIRD PARTY MATTERS: OWNERSHIP RIGHTS
     -------------------------------------

    The parties agree that Corporation shall bear and pay for royalty
obligations to third parties with respect to asserted ownership rights to TPO
and/or PPO Technology which would otherwise be required from Amgen and/or Kirin.
Such third party royalty payments shall be an obligation of Corporation (in
addition to any royalty payments which K-A is otherwise obligated to make). It
is agreed that the right to reach agreement with a third party respecting this
matter shall be handled by the shareholder(s) whose territory(ies) is (are)
affected. For example, if any third party person and/or entity makes a claim for
TPO and/or PPO royalty payments and it affects only the territory of Japan,
Kirin shall have the sole responsibility of negotiating a third party royalty
rate payable by K-A which shall be binding on all parties hereto.

3.   PPO TECHNOLOGY
     --------------

     The parties agree that upon the successful completion of the R & D Project
for PPO, as more fully set forth in the Research, Development, Technology
Disclosure and License Agreement: PPO, all rights in and to the PPO Technology
shall be promptly licensed and/or transferred to Corporation.  Additionally,
Amgen shall, at that time, exclusively license to Corporation on a royalty-free
world-wide basis its Core Technology relating to PPO.

4.   FURTHER INSTRUMENTS
     -------------------

     Each party hereto agrees to perform any and all further acts and execute
and deliver any and all further documents and/or instruments which may be
reasonable or necessary to carry out the provisions and purposes of this
Amendment No. 3 to the Shareholders' Agreement.

                            [SIGNATURE PAGE FOLLOWS]

                                      -2-
<PAGE>

     IN WITNESS WHEREOF, the undersigned have caused this Amendment No. 3 to be
executed as of the first date written above by their duly authorized
representatives in a manner legally binding upon them.

                              KIRIN BREWERY COMPANY, LTD.,
                              a Japanese corporation

                              By    /s/Shinkichi Kubo
                                ---------------------------------------
                                 Shinkichi Kubo, Senior
                                 Managing Director

                                                            "Kirin"

                              AMGEN, a California corporation

                              By    /s/George B. Rathmann
                                ---------------------------------------
                                 George B. Rathmann, President

                                                            "Amgen"

                              KIRIN-AMGEN, INC.,
                              a California corporation

                              By    /s/Shinkichi Kubo
                                ---------------------------------------
                               Shinkichi Kubo Its Chairman
                               ---------------    --------

                                                            "Corporation"

                                      -3-

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