SecProbe.io

July 27, 2010

Dr. Michael D. West, PhD.
Chief Executive Officer
BioTime, Inc.
1301 Harbor Bay Parkway, Suite 100
Alameda, California 94502

Re: BioTime, Inc.
0B Form 10-K for the Fiscal Year Ended December 31, 2009
Definitive Proxy Statement
Filed April 30, 2010
File No. 001-12830

Dear Dr. West:

We have reviewed your filings and have the following comments.  In some of our
comments, we may ask you to provide us with  information so we may better understand your
disclosure.

Please respond to this letter within ten business days by amending your Form 10-K for
the year ended December 31, 2009, by providing the requested information, or by advising us when you will provide the requested response.  If you do not believe our comments apply to your
facts and circumstances or do not believe an am endment is appropriate, please tell us why in
your response.  Please furnish us a letter on E DGAR under the form type label CORRESP that
keys your responses to our comments.
 We may have further comments after review ing your amended filing and response to our
comments.   Form 10-K for the Fiscal Year Ended December 31, 2009

 General

1. Please include a typed signature in the report of independent register ed public accounting
firm as required by Item 302 of Regulation S-T.

2. Your disclosure refers to two business se gments. Please tell us the factors that you
considered in concluding that you are ope rating in a single busi ness segment and the
disclosure under ASC 280 was not required.

Dr. Michael D. West, PhD. BioTime, Inc. July 27, 2010 Page 2

Business

 Stem Cells and Products for Regene rative Medicine Research, page 4

3. We note that you received a $4.7 million gr ant from the California Institute of
Regenerative Medicine in 2009.  We further note your disclosure that the proceeds from
the grant represented 28.5% of the Compa ny’s revenues for 2009 and that the Company
will be dependent on the grant as a principal source of revenues for the near future.  Please file any agreement underlying the grant from CIRM as an exhibit to your filing.
Alternatively, provide us your analysis as to why you are not substantially dependent
upon this agreement.
 Licensed Stem Cell Technology and Stem Cell Product Development Agreements, page 8

4. Please revise your disclosure to disclose th e respective terminati on provisions for your
license and sublicense  agreements with Advanced Cell Technology, Inc. in relation to
ACTCellerate technolog y and iPS technology.

5. Please revise your disclosure to disclose th e respective term and termination provisions
for your Product Production and Distribution Ag reement with Lifeline Cell Technology,
LLC and your Stem Cell Agreement with Reproductive Genetics Institute.
 Licensing and Sale of Plasma Volume Expander Products, page 20

6. Please revise your disclosure to disclose th e respective term and termination provisions
for your license agreement with CJ Corp. and your collaboration agreements with
Summit Pharmaceuticals International Corporation.
 Management’s Discussion and Analysis of Financial Condition and Results of

 Operations, page 39

7. You have not included disclosure of critical accounting estimates, which provide
investors with an understanding of the uncerta inties in applying critical accounting
policies and the likelihood that materially  different amounts would be reported under
different conditions or us ing different assumptions. Please identify your critical
accounting policies. Discuss and quantify the uncertainties in applying these critical
accounting policies, th e related methods and key assumptions and the effect that
reasonably likely changes in these key assumptions may have on your financial
statements. Refer to the Commission’s In terpretative MD&A Guidance (Release No. 33-
8350 dated December 29, 2003).

Dr. Michael D. West, PhD. BioTime, Inc. July 27, 2010 Page 3

Results of Operations, page 40

8. Please refer to the Division of Corporati on Finance “Current Issues and Rulemaking
Projects Quarterly Update” unde r section VIII – Industry Sp ecific Issues – Accounting
and Disclosure by Companies Engaged in Research and Development Activities.  You can find it at the following website address: http://www.sec.gov/divisions/c orpfin/cfcrq032001.htm#secviii
.
 Please disclose the following information fo r each of your significant research and
development projects:
• The current status of the project;
• The costs incurred during each period presented and to date on the project
including costs reimbursements to  your co-development partners:
• The timing and estimated costs nece ssary to complete the project;
• The anticipated completion dates;
• The period in which material net cash inflows are expected to commence.

If you do not maintain research and deve lopment costs by project, provide other
quantitative or qualitative di sclosure that indicates th e amount of the company’s
resources being used on the project. To the ex tent that the amount or range of costs and
timing to complete the project are not estima ble, disclose those facts and circumstances
that preclude you from making reasonable estimates.
 Liquidity and Capital Resources

 Contractual obligations, page 45

9. Please provide the tabular disclosure re quired by Item 303 (a) (5) of Regulation
S-K.  Include the applicab le obligations under your li cense and co-development
arrangements, such as your royalty obligations  to Summit. To the ex tent that the amount
or range of these obligations is not estimable , disclose those facts and circumstances that
preclude you from making reasonable estimates.
Notes to the Consolidated Financial Statements

 5.Royalty Obligations and Deferred License Fees, page 59

10. The co-development agreement with Summit s tipulates that revenues from Hextend and
PentaLyte sales will be shared as follows:  BioTime 40% and Summit 60%. Please tell us
whether you are reporting these activities on a net or gross basis and explain the factors
considered in determining your accounting treatment. If you are reporting these activities on a gross basis, explain how you have accounted for Summit’s share of these revenues. Revise your disclosure accordingly.

Dr. Michael D. West, PhD. BioTime, Inc. July 27, 2010 Page 4

11. As of December 31, 2009, you appear to have deferred all license fee payments under
your contractual arrangements with WARF, Lifeline, ACT, the Kirin Sublicense and
RCI, which to date have not been subject to amortization. Please explain to us and
disclose your basis for this accounting treatment, including the method to be used for
amortizing these deferred license fees.
 Definitive Proxy Statement

 Executive Compensation, page 17

12. We note your disclosure that the annual bonus for executive officers is based on the
achievement of personal and company perfor mance goals and that your Chief Executive
Officer and Chief Operati ng Officer were awarded a nnual incentive bonuses of $50,000
and $30,000 respectively in 2009.  However, we note that you have omitted significant disclosure regarding these bonus  awards.  Please revise this  information to include the
following:

• The personal and company performance objectives applicable to each named
executive officer and used to determine their annual bonuses and how each
objective was weighted, if applicable. To the extent that any of the performance
objectives were quantitative, your disclo sure should also be quantitative;
• The threshold, target, and maximum levels  of achievement of each performance
measure, if applicable;
• The intended relationship between the le vel of achievement of company and
personal performance objectives and the amount of bonus to be awarded;
• The evaluation by the Committee of the level of achievement by each named
executive officer of the company and pers onal performance objectives applicable
to them; and
• Any other factors that were considered by the Committee that modified the actual
cash bonuses awarded.

      We urge all persons who are responsible for the accuracy and ade quacy of the disclosure
in the filing to be certain that the filing include s the information the Securities Exchange Act of
1934 and all applicable Exchange Act rules requir e.  Since the company and its management are
in possession of all facts relating to a company’s disclosure, they are responsible for the accuracy
and adequacy of the disclosures they have made.

 In responding to our comments, please provi de a written statement from the company
acknowledging that:

• the company is responsible for the adequacy an d accuracy of the disclo sure in the filing;
• staff comments or changes to disclosure in response to staff comments do not foreclose
the Commission from taking any action with respect to the filing; and

Dr. Michael D. West, PhD. BioTime, Inc. July 27, 2010 Page 5

• the company may not assert staff comments as  a defense in any proceeding initiated by
the Commission or any person under the federa l securities laws of  the United States.

Please contact Frank Wyman, St aff Accountant, at (202) 551-3660 or Lisa Vanjoske,
Assistant Chief Accountant, at (202) 551-3614, if you have an y questions regarding the
processing of your response, as well as any questions regarding comments on the financial
statements and related matters.  You may contact  Bryan Pitko, Staff Attorney, at (202) 551-3203
with questions on any of the othe r comments.  In this regard, do not hesitate to contact me at
(202) 551-3679.

Sincerely,

Jim B. Rosenberg
Senior Assistant Chief Accountant