Share Exchange and Contribution Agreement	9 Months Ended
Sep. 30, 2012
Share Exchange and Contribution Agreement [Abstract]
Share Exchange and Contribution Agreement	9. Share Exchange and Contribution Agreement On July 24, 2012, LifeMap entered into a Share Exchange and Contribution Agreement (the "LifeMap Agreement") with Alfred D. Kingsley and a company that he controls, Greenway Partners, L.P., pursuant to which Mr. Kingsley and Greenway agreed to contribute to LifeMap, in the aggregate, BioTime common shares having an aggregate value of not less than $2,000,000 and not more than $3,000,000, determined as provided in the LifeMap Agreement, in exchange for shares of LifeMap common stock at an initial price of $1.75 per LifeMap share. Under the LifeMap Agreement, Mr. Kingsley and Greenway contributed 420,000 BioTime shares to LifeMap and received in exchange 1,143,864 shares of LifeMap common stock. The number of shares of LifeMap common stock issued in exchange for the BioTime shares was determined by multiplying the number of BioTime shares contributed by $4.7661, the highest weighted average closing price per share on the NYSE MKT for any ten trading days during the period from July 1, 2012 through July 31, 2012, and dividing that amount by $1.75, which was the Exchange Price per share of LifeMap common stock. The Exchange Price per share of LifeMap common stock may be reduced, and additional shares of LifeMap common stock may be issued in exchange for the BioTime shares received by LifeMap, if LifeMap sells shares of its common stock or other securities exercisable or exchangeable for, or convertible into, its common stock for a price per share of common stock lower than $1.75, other than pursuant to options granted under LifeMap's stock option plan, on or before December 31, 2012. As a result of this investment, our ownership dropped from 86.3% to $77.1% as of July 30, 2012. As of September 30, 2012, the 420,000 BioTime shares held by LifeMap are presented as treasury stock at a cost of $2,001,762. In accordance with the License and Research Assignment Agreement dated May 14, 2012 between Yeda Research and Development Company, Ltd ("Yeda") and BioTime in connection with the merger of XenneX, Inc. and LifeMap in May 2012, if additional LifeMap shares up to $3,000,000 are issued, LifeMap will issue shares to Yeda in order to maintain their 3.75% ownership in the issued and outstanding LifeMap shares on a fully diluted basis. As a result of the $2,001,762 investment in LifeMap aforementioned, LifeMap issued Yeda 44,566 LifeMap common stock with an estimated fair value of $78,000. Mr. Kingsley and Greenway have agreed to contribute additional BioTime Shares to LifeMap so that the total number of BioTime shares so contributed will have a total value of not more than $3,000,000. The additional BioTime Shares so contributed will be valued as of November 30, 2012 at the highest weighted average closing price per share on the NYSE MKT for any ten trading days during the period from August 1, 2012 through November 30, 2012. Our ownership interest in LifeMap will be further reduced from 77.1% to approximately 73.2% as a result of the exchange of BioTime shares for LifeMap common stock by Mr. Kingsley and Greenway, assuming that LifeMap does not issue any additional shares of its common stock. We have registered the BioTime Shares received by LifeMap for resale under the Securities Act of 1933, as amended.

9. Share Exchange and Contribution Agreement

On July 24, 2012, LifeMap entered into a Share Exchange and Contribution Agreement (the "LifeMap Agreement") with Alfred D. Kingsley and a company that he controls, Greenway Partners, L.P., pursuant to which Mr. Kingsley and Greenway agreed to contribute to LifeMap, in the aggregate, BioTime common shares having an aggregate value of not less than $2,000,000 and not more than $3,000,000, determined as provided in the LifeMap Agreement, in exchange for shares of LifeMap common stock at an initial price of $1.75 per LifeMap share.

Under the LifeMap Agreement, Mr. Kingsley and Greenway contributed 420,000 BioTime shares to LifeMap and received in exchange 1,143,864 shares of LifeMap common stock. The number of shares of LifeMap common stock issued in exchange for the BioTime shares was determined by multiplying the number of BioTime shares contributed by $4.7661, the highest weighted average closing price per share on the NYSE MKT for any ten trading days during the period from July 1, 2012 through July 31, 2012, and dividing that amount by $1.75, which was the Exchange Price per share of LifeMap common stock. The Exchange Price per share of LifeMap common stock may be reduced, and additional shares of LifeMap common stock may be issued in exchange for the BioTime shares received by LifeMap, if LifeMap sells shares of its common stock or other securities exercisable or exchangeable for, or convertible into, its common stock for a price per share of common stock lower than $1.75, other than pursuant to options granted under LifeMap's stock option plan, on or before December 31, 2012. As a result of this investment, our ownership dropped from 86.3% to $77.1% as of July 30, 2012. As of September 30, 2012, the 420,000 BioTime shares held by LifeMap are presented as treasury stock at a cost of $2,001,762.

In accordance with the License and Research Assignment Agreement dated May 14, 2012 between Yeda Research and Development Company, Ltd ("Yeda") and BioTime in connection with the merger of XenneX, Inc. and LifeMap in May 2012, if additional LifeMap shares up to $3,000,000 are issued, LifeMap will issue shares to Yeda in order to maintain their 3.75% ownership in the issued and outstanding LifeMap shares on a fully diluted basis. As a result of the $2,001,762 investment in LifeMap aforementioned, LifeMap issued Yeda 44,566 LifeMap common stock with an estimated fair value of $78,000.

Mr. Kingsley and Greenway have agreed to contribute additional BioTime Shares to LifeMap so that the total number of BioTime shares so contributed will have a total value of not more than $3,000,000. The additional BioTime Shares so contributed will be valued as of November 30, 2012 at the highest weighted average closing price per share on the NYSE MKT for any ten trading days during the period from August 1, 2012 through November 30, 2012.

Our ownership interest in LifeMap will be further reduced from 77.1% to approximately 73.2% as a result of the exchange of BioTime shares for LifeMap common stock by Mr. Kingsley and Greenway, assuming that LifeMap does not issue any additional shares of its common stock.

We have registered the BioTime Shares received by LifeMap for resale under the Securities Act of 1933, as amended.