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                                                                   EXHIBIT 10.47

                          SALE AND LEASEBACK AGREEMENT


               THIS SALE AND LEASEBACK AGREEMENT (this "Agreement"), is made as
of May 6, 1998, among Progenitor, Inc., a Delaware corporation ("Seller"), and
Transamerica Business Credit Corporation, a Delaware corporation ("Buyer").

                              W I T N E S S E T H :


               WHEREAS, Seller is the owner of the equipment more particularly
described on Exhibit II hereto (the "Equipment");

               WHEREAS, Seller desires to sell to Buyer and Buyer desires to
purchase from Seller the Equipment; and

               WHEREAS, Buyer, as a condition to such purchase, wishes to lease
to Seller and Seller wishes to lease from Buyer the Equipment under the terms
and conditions of the Master Lease Agreement dated as of May 1, 1998 and
Schedule No. 1 thereto (collectively, as amended, supplemented or otherwise
modified from time to time, the "Lease") between Buyer, as lessor, and Seller,
as lessee.

               NOW, THEREFORE, in consideration of the premises herein contained
and other good and valuable consideration, the receipt and sufficiency of which
are hereby acknowledged, the parties hereto hereby agree as follows:

               1. AMOUNT AND TERMS OF PURCHASE.

                      (a) Subject to the terms and conditions of this Agreement,
and in reliance upon the representations and warranties of the Seller herein set
forth, the Buyer agrees to purchase all of the Seller's right, title and
interest in and to all of the Equipment such that the Buyer will become the
owner of all such Equipment for all purposes whatsoever. The Seller hereby
agrees that the Buyer is under no obligation to purchase any other equipment now
or in the future and shall not assert a claim that the Buyer may have any such
obligation.

                      (b) The price to be paid by the Buyer with respect to the
purchase of the Equipment (the "Purchase Price") is $889,987.77. The Purchase
Price shall be payable to the Seller on the Lease Commencement Date (as defined
in the Lease).

                      (c) The Seller shall pay any and all applicable federal,
state, county or local taxes and any and all present or future taxes or other
governmental charges arising in connection with the sale of the Equipment
hereunder, including sales, use or occupation taxes due upon the purchase by the
Buyer.

                      (d) The purchase of the Equipment shall be evidenced by a
bill of sale, substantially in the form attached hereto as Exhibit A (the "Bill
of Sale"), duly executed by the Seller.


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               2. CONDITIONS TO PURCHASE. The obligation of the Buyer to
purchase the Equipment is subject to the following conditions:

                      (a) The Buyer shall have received this Agreement, duly
executed by the Seller.

                      (b) The Buyer shall have received the Bill of Sale, duly
executed by the Seller.

                      (c) The Buyer shall have received the Lease, duly executed
by the Seller.

                      (d) The Buyer shall have received resolutions of the Board
of Directors of the Seller approving and authorizing the execution, delivery and
performance by the Seller of this Agreement, the Lease and the notices and other
documents to be delivered by the Seller hereunder and thereunder (collectively,
the "Sale and Leaseback Documents").

                      (e) The Buyer shall have received the certificate of title
or similar evidence of ownership with respect to each item of Equipment and
Uniform Commercial Code financing statements covering the Equipment in form and
substance satisfactory to the Buyer, duly executed by the Seller.

                      (f) No material adverse change has occurred with respect
to the business, prospects, properties, results of operations, assets,
liabilities or condition (financial or otherwise) of the Seller and its
affiliates, taken as a whole, since September 30, 1997.

                      (g) The Buyer shall have received all warranties and other
documentation received or executed by Seller in connection with the original
acquisition of the Equipment by the Seller (and by its execution hereof the
Seller hereby assigns to the Buyer all such warranties and other Documentation).

                      (h) The Buyer shall have received an opinion of Seller's
counsel, substantially in the form attached hereto as Exhibit B.

                      (i) The Buyer shall have received such other approvals,
opinions or documents as the Buyer may reasonably request.

               3. REPRESENTATION AND WARRANTIES. To induce the Buyer to enter
into this Agreement, the Seller represents and warrants to the Buyer that:

                      (a) The Seller is duly authorized to execute, deliver and
perform its obligations under each of the Sale and Leaseback Documents and all
corporate action required on its part for the due execution, delivery and
performance of the transactions contemplated herein and therein has been duly
and effectively taken.


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                      (b) The execution, delivery and performance by the Seller
of each of the Sale and Leaseback Documents and the consummation of the
transactions contemplated herein and therein does not and will not violate any
provision of, or result in a default under, the Seller's Articles or
Certificates of Incorporation or By-laws or any indenture or agreement to which
the Seller is a party or to which its assets are bound or any order, permit,
law, statute, code, ordinance, rule, regulation, certificate or any other
requirement of any governmental authority or regulatory body to which the Seller
is subject, or result in the creation or imposition of any mortgage, deed of
trust, pledge, security interest, lien or encumbrance of any kind upon or with
respect to the Equipment or any proceeds thereof, other than those in favor of
the Buyer as contemplated by the Sale and Leaseback Documents.

                      (c) No authorization or approval or other action by, and
no notice to or filing with, any governmental authority or regulatory body is
required for the due execution, delivery and performance by the Seller of any of
the Sale and Leaseback Documents to which it is a party.

                      (d) Each Sale and Leaseback Document to which the Seller
is a party constitutes or will constitute, when delivered hereunder, the legal,
valid and binding obligation of the Seller enforceable against the Seller in
accordance with its respective terms, except as such enforceability may be (i)
limited by the effect of applicable bankruptcy, insolvency, reorganization or
similar laws affecting the enforcement of creditors' rights generally or (ii)
subject to the effect of general principles of equity (regardless of whether
such enforceability is considered in a proceeding at equity or at law).

                      (e) There are no actions, suits, or proceedings pending,
threatened against or affecting the Seller which seek to enjoin, prohibit or
restrain the consummation of any of the transactions contemplated hereby or by
the other Sale and Leaseback Documents.

                      (f) Each item of Equipment is owned by the Seller free and
clear of any liens and encumbrances of any kind or description. Upon purchase of
the Equipment hereunder, the Buyer will acquire good and marketable title in and
to the Equipment.

All representations and warranties herein shall survive the execution of this
Agreement and the purchase of the Equipment.

               4. INDEMNITIES. The Seller agrees to indemnify, defend, and save
harmless the Buyer and its officers, directors, employees, agents, and
attorneys, and each of them (the "Indemnified Parties"), from and against all
claims, actions, suits, and other legal proceedings, damages, costs, interest,
charges, counsel fees and other expenses and penalties (collectively, the
"Indemnified Amounts") which any of the Indemnified Parties may sustain or incur
by reason of or arising out of (i) the Seller's ownership of any Equipment prior
to the date on which such Equipment is sold to the Buyer, or the Seller's acts
or omissions prior to such date under, in connection with or relating to such
Equipment or any of the Sale and Leaseback Documents, (ii) the operation,
maintenance or use of such Equipment prior to such date, (iii) the inaccuracy 


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of any of the Seller's representations or warranties contained in any of the
Sale and Leaseback Documents, (iv) the breach of any of the Seller's covenants
contained in any of the Sale and Leaseback Documents, (v) any loss or damage to
any Equipment in excess of the deductible which is not paid by insurance or (vi)
any sales, use, excise and other taxes, charges, and fees (including, without
limitation, income, franchise, business and occupation, gross receipts, sales,
use, licensing, registration, titling, personal property, stamp and interest
equalization taxes, levies, imposts, duties, charges or withholdings of any
nature), and any fines, penalties or interest thereon, imposed or levied by any
governmental body, agency or tax authority upon or in connection with the
Equipment, its acquisition, ownership, delivery, leasing, possession, use or
relocation or otherwise in connection with the transactions contemplated by each
Sale and Leaseback Document.

               5. REMEDIES. Upon the Seller's violation of or default under any
provision of this Agreement, the Buyer may (subject to the provisions of the
other Sale and Leaseback Documents) proceed to protect and enforce its rights
either by suit in equity or by action at law or both, whether for the specific
performance of any covenant or agreement contained herein or in aid of the
exercise of any power granted in any Sale and Leaseback Document; it being
intended that the remedies contained in any Sale and Leaseback Document shall be
cumulative and shall be in addition to every other remedy given under such Sale
and Leaseback Document or now or hereafter existing at law or in equity or by
statute or otherwise.

               6. AMENDMENTS, ETC. No amendment or waiver of any provision of
this Agreement, nor consent to any departure therefrom, shall in any event be
effective unless the same shall be in writing and signed by the Buyer, and then
such waiver or consent shall be effective only in the specific instance and for
the specific purpose for which given.

               7. NOTICES, ETC. All notices and other communications provided
for hereunder shall be in writing and sent:

               if to the Seller, at its address at:

                      PROGENITOR, INC.
                      4040 CAMPBELL AVENUE
                      MENLO PARK, CALIFORNIA  94025
                      Attention:   Chief Financial Officer
                      Telephone No.:  650-617-0880
                      Telecopy No.:    650-617-0883


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               if to the Buyer, at its address at:

                      Transamerica Business Credit Corporation
                      Technology Finance Division
                      76 Batterson Park Road
                      Farmington, Connecticut 06032-2571
                      Attention:  Assistant Vice President,
                               Lease Administration
                      Telephone No.:  860-677-6466
                      Telecopy No.:    860-677-6766

               with a copy to:

                      Transamerica Business Credit Corporation
                      9399 West Higgins Road
                      Rosemont, Illinois  60018
                      Attention:  Legal Department
                      Telephone No.:  847-685-1106
                      Telecopy No.:    847-685-1143

or to such other address as shall be designated by such party in a written
notice to the other party. All such notices shall be deemed given (i) if sent by
certified or registered mail, three days after being postmarked, (ii) if sent by
overnight delivery service, when received at the above stated addresses or when
delivery is refused and (iii) if sent by facsimile transmission, when receipt of
such transmission is acknowledged.

               8. NO WAIVER; REMEDIES. No failure on the part of the Buyer to
exercise, and no delay in exercising, any right hereunder shall operate as a
waiver thereof, nor shall any single or partial exercise of any such right
preclude any other or further exercise thereof or the exercise of any other
right. The remedies herein provided are cumulative and not exclusive of any
remedies provided by law.

               9. BENEFIT. Without the prior written consent of the Buyer, the
Seller may not transfer, assign or delegate any of its rights, duties or
obligations hereunder.

               10. BINDING EFFECT. This Agreement shall be binding upon and
inure to the benefit of the Seller and the Buyer and their respective successors
and assigns.

               11. GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED BY, AND SHALL
BE CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF ILLINOIS WITHOUT
GIVING EFFECT TO THE CONFLICTS OF LAW PRINCIPLES THEREOF.


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               12. EXECUTION IN COUNTERPARTS. This Agreement may be executed in
any number of counterparts, each of which shall constitute an original and all
of which taken together shall constitute one and the same agreement.

               13. SEVERABILITY. If one or more of the provisions contained in
this Agreement shall be invalid, illegal, or unenforceable in any respect, the
validity, legality, and enforceability of the remaining provisions contained
herein, and any other application thereof, shall not in any way be affected or
impaired thereby.

               14. SUBMISSION TO JURISDICTION. ALL DISPUTES ARISING UNDER OR IN
CONNECTION WITH THIS AGREEMENT BETWEEN THE PARTIES HERETO, WHETHER SOUNDING IN
CONTRACT, TORT, EQUITY OR OTHERWISE, SHALL BE RESOLVED ONLY BY STATE AND FEDERAL
COURTS LOCATED IN ILLINOIS, AND THE COURTS TO WHICH AN APPEAL THEREFROM MAY BE
TAKEN; PROVIDED, HOWEVER, THAT THE BUYER SHALL HAVE THE RIGHT, TO THE EXTENT
PERMITTED BY APPLICABLE LAW, TO PROCEED AGAINST THE SELLER OR ITS PROPERTY IN
ANY LOCATION REASONABLY SELECTED BY THE BUYER IN GOOD FAITH TO ENABLE THE BUYER
TO REALIZE ON SUCH PROPERTY, OR TO ENFORCE A JUDGMENT OR OTHER COURT ORDER IN
FAVOR OF THE BUYER. EACH PARTY AGREES THAT IT WILL NOT ASSERT ANY PERMISSIVE
COUNTERCLAIMS, SETOFFS OR CROSS-CLAIMS IN ANY PROCEEDING BROUGHT BY THE BUYER;
IT BEING UNDERSTOOD THAT THIS SENTENCE DOES NOT PRECLUDE THE SELLER FROM
ASSERTING COMPULSORY COUNTERCLAIMS. THE SELLER WAIVES ANY OBJECTION THAT IT MAY
HAVE TO THE LOCATION OF THE COURT IN WHICH THE BUYER HAS COMMENCED A PROCEEDING,
INCLUDING, WITHOUT LIMITATION, ANY OBJECTION TO THE LAYING OF VENUE OR BASED ON
FORUM NON CONVENIENS.

               15. JURY TRIAL. THE PARTIES HERETO EACH HEREBY WAIVE TO THE
FULLEST EXTENT PERMITTED BY LAW ANY RIGHT TO A TRIAL BY JURY IN ANY ACTION OR
PROCEEDING ARISING UNDER OR IN CONNECTION WITH THIS AGREEMENT.


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               IN WITNESS WHEREOF, the parties hereto have caused this Agreement
to be executed by their respective officers hereunto duly authorized, as of the
first date written above.


                            PROGENITOR, INC.


                            By: /s/ Mark Bagnall
                               -------------------------------
                               Name: Mark Bagnall
                               Title: Vice President & CFO



                            TRANSAMERICA BUSINESS CREDIT CORPORATION



                            By: /s/ Gary P. Moro
                               -------------------------------
                               Name: Gary P. Moro
                               Title:



Exhibit II-  Equipment
Exhibit A-   Bill of Sale
Exhibit B-   Opinion of Seller's Counsel


Form 14


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                                    EXHIBIT A


                                  BILL OF SALE


               KNOW ALL PERSONS BY THESE PRESENTS PROGENITOR, INC. (the
"Seller"), for Eight Hundred Eighty Nine Thousand, Nine Hundred Eighty Seven and
77/100 Dollars ($889,987.77) and other valuable consideration to it in hand
paid, receipt of which is hereby acknowledged, does unconditionally, absolutely
and irrevocably grant, sell, assign, transfer and convey unto TRANSAMERICA
BUSINESS CREDIT CORPORATION and its assignees or successors (collectively, the
"Buyer"), all of the Seller's right, title and interest in and to the equipment
described on Exhibit II hereto (collectively, the "Equipment").

               TO HAVE AND TO HOLD said Equipment unto the said Buyer, to and
for its use forever.

               AND, the Seller hereby warrants, covenants and agrees that it (a)
has good and marketable title to the Equipment, free and clear of any liens and
other encumbrances; and (b) will warrant and defend the sale of the Equipment
against any and all persons claiming against such title.

               IN WITNESS WHEREOF the Seller has caused this instrument to be
duly executed and delivered as of this 13th day of May, 1998.



                             PROGENITOR, INC.


                             By:  ______________________________
                                    Name:
                                    Title:


Form 14