Asset Contribution Agreement	3 Months Ended
Mar. 31, 2013
Asset Contribution Agreement [Abstract]
Asset Contribution Agreement	9. Asset Contribution Agreement On January 4, 2013, BioTime and Asterias entered into an Asset Contribution Agreement with Geron Corporation ("Geron") pursuant to which BioTime and Geron will concurrently contribute certain assets to Asterias in exchange for shares of Asterias common stock. Closing of the asset contribution transaction is expected to occur no later than September 30, 2013. Pursuant to the Asset Contribution Agreement, Geron has agreed to contribute certain assets related to its discontinued stem cell research and development programs, including certain patents and know-how related to human embryonic stem cells; certain biological materials and reagents; certain laboratory equipment; certain contracts; and certain product clinical trials, in exchange for shares of Asterias common stock, and BioTime has agreed to contribute 8,902,077 common shares; warrants to subscribe for and purchase 8,000,000 additional common shares; $5,000,000 in cash; 10% of the shares of common stock of OrthoCyte Corporation issued and outstanding on the date of the Asset Contribution Agreement; 6% of the ordinary shares of our subsidiary Cell Cure Neurosciences issued and outstanding on the date of the Asset Contribution Agreement; and a quantity of certain human hES cell lines produced under cGMP, and a non-exclusive, world-wide, royalty-free license to use those hES cell lines and certain patents pertaining to stem cell differentiation technology, in exchange for Asterias common stock and warrants to purchase Asterias common stock. A private investor has agreed to contribute $5 million in cash to Asterias for 2,136,000 shares of Asterias Series B common stock, and warrants to purchase 350,000 additional shares of Asterias Series B common stock. That investment will be made in conjunction with the closing under the Asset Contribution Agreement. If for any reason the private investor fails to make the $5 million contribution, BioTime will contribute cash, BioTime common shares, or a combination of cash and BioTime common shares to Asterias in an amount equal to the cash not contributed by the private investor. The same private investor invested $5 million in BioTime by purchasing, in two tranches, an aggregate of 1,350,000 BioTime common shares and warrants to purchase approximately 650,000 additional BioTime common shares. The first tranche of $2,000,000 was funded during January 2013, and BioTime issued to the investor 540,000 common shares and 259,999 warrants. The second tranche of $3,000,000 was funded on April 10, 2013, and BioTime issued to the investor 810,000 common shares and 389,999 warrants. Asterias will assume all obligations and liabilities in connection with the assets contributed by Geron, to the extent such obligations and liabilities arise after the closing date of the Asset Contribution Agreement, including certain obligations and liabilities to provide follow-up procedures with patients who participated in Geron's clinical trials. Upon the closing under the Asset Contribution Agreement, BioTime will own 21,773,340 shares of Asterias Series B common stock and Geron will own 6,537,779 shares of Asterias Series A common stock. Upon the sale of Asterias shares to the private investor, the private investor will own 2,136,000 shares of Asterias Series B common stock. Geron has agreed to distribute to its stockholders on a pro rata basis the shares of Asterias Series A common stock that Geron receives in the asset contribution transaction following the closing under the Asset Contribution Agreement. Following that distribution by Geron, Asterias will distribute to the holders of its Series A common stock on a pro rata basis the 8,000,000 BioTime warrants that it receives under the Asset Contribution Agreement. Following the distributions of the Asterias Series A common stock by Geron to its stockholders, BioTime will own, including the shares of Asterias Series B common stock that BioTime presently owns, approximately 71.6% of the outstanding Asterias common stock, the Geron stockholders will own approximately 21.4% of the outstanding Asterias common stock and the private investor will own approximately 7.0%, of the outstanding Asterias common stock. BioTime will also receive warrants to purchase 3,150,000 shares of Asterias Series B common stock and the private investor will receive warrants to purchase 350,000 shares of Asterias Series B common stock (the "Asterias Warrants"). The Asterias Warrants will have an exercise price of $5.00 per share and a term of three years. The exercise price per share and number of shares that may be purchased upon the exercise of the Asterias Warrants will be subject to adjustment in the event of any Asterias stock split, reverse stock split, stock dividend, reclassification of shares and certain other transactions. The Asterias Series A and Series B common stock will be identical in most respects, however, Asterias will be entitled to make certain distributions or pay dividends, other than stock dividends, on its Series A common stock, without making a distribution or paying a dividend on its Series B common stock. The Asterias Series B common stock may be converted into Asterias Series A common stock, on a share for share basis, at Asterias' election, only after Geron distributes to its stockholders the Asterias Series A common stock issued under the Asset Contribution Agreement and Asterias subsequently distributes to the Asterias Series A common stock holders the 8,000,000 BioTime warrants that Asterias will receive from BioTime under the Asset Contribution Agreement. Closing of the asset contribution transaction is subject to certain negotiated conditions, including: the effectiveness of registration statements under the Securities Act of 1933 filed by BioTime and Asterias, and the approval by BioTime shareholders of the issuance of BioTime shares and warrants in the transaction, and an amendment of BioTime's Articles of Incorporation to increase its authorized capital stock (the "Shareholder Proposals"). Closing of the cash contribution by the private investor is also subject to certain negotiated closing conditions, including the closing of the asset contribution transaction. BioTime will be required to pay Geron a termination fee of $1.8 million in certain circumstances if the Asset Contribution Agreement is terminated if (a) the BioTime board of directors withdraws its recommendation to BioTime shareholders to approve the Shareholder Proposals, (b) certain BioTime directors materially breach the Support Agreements under which they and certain of their affiliates have agreed to vote their BioTime shares in favor of the Shareholder Proposals, or (c) BioTime's shareholders do not vote to approve the Shareholder Proposals.

9. Asset Contribution Agreement

On January 4, 2013, BioTime and Asterias entered into an Asset Contribution Agreement with Geron Corporation ("Geron") pursuant to which BioTime and Geron will concurrently contribute certain assets to Asterias in exchange for shares of Asterias common stock. Closing of the asset contribution transaction is expected to occur no later than September 30, 2013.

Pursuant to the Asset Contribution Agreement, Geron has agreed to contribute certain assets related to its discontinued stem cell research and development programs, including certain patents and know-how related to human embryonic stem cells; certain biological materials and reagents; certain laboratory equipment; certain contracts; and certain product clinical trials, in exchange for shares of Asterias common stock, and BioTime has agreed to contribute 8,902,077 common shares; warrants to subscribe for and purchase 8,000,000 additional common shares; $5,000,000 in cash; 10% of the shares of common stock of OrthoCyte Corporation issued and outstanding on the date of the Asset Contribution Agreement; 6% of the ordinary shares of our subsidiary Cell Cure Neurosciences issued and outstanding on the date of the Asset Contribution Agreement; and a quantity of certain human hES cell lines produced under cGMP, and a non-exclusive, world-wide, royalty-free license to use those hES cell lines and certain patents pertaining to stem cell differentiation technology, in exchange for Asterias common stock and warrants to purchase Asterias common stock.

A private investor has agreed to contribute $5 million in cash to Asterias for 2,136,000 shares of Asterias Series B common stock, and warrants to purchase 350,000 additional shares of Asterias Series B common stock. That investment will be made in conjunction with the closing under the Asset Contribution Agreement. If for any reason the private investor fails to make the $5 million contribution, BioTime will contribute cash, BioTime common shares, or a combination of cash and BioTime common shares to Asterias in an amount equal to the cash not contributed by the private investor.

The same private investor invested $5 million in BioTime by purchasing, in two tranches, an aggregate of 1,350,000 BioTime common shares and warrants to purchase approximately 650,000 additional BioTime common shares. The first tranche of $2,000,000 was funded during January 2013, and BioTime issued to the investor 540,000 common shares and 259,999 warrants. The second tranche of $3,000,000 was funded on April 10, 2013, and BioTime issued to the investor 810,000 common shares and 389,999 warrants.

Asterias will assume all obligations and liabilities in connection with the assets contributed by Geron, to the extent such obligations and liabilities arise after the closing date of the Asset Contribution Agreement, including certain obligations and liabilities to provide follow-up procedures with patients who participated in Geron's clinical trials.

Upon the closing under the Asset Contribution Agreement, BioTime will own 21,773,340 shares of Asterias Series B common stock and Geron will own 6,537,779 shares of Asterias Series A common stock. Upon the sale of Asterias shares to the private investor, the private investor will own 2,136,000 shares of Asterias Series B common stock.

Geron has agreed to distribute to its stockholders on a pro rata basis the shares of Asterias Series A common stock that Geron receives in the asset contribution transaction following the closing under the Asset Contribution Agreement. Following that distribution by Geron, Asterias will distribute to the holders of its Series A common stock on a pro rata basis the 8,000,000 BioTime warrants that it receives under the Asset Contribution Agreement.

Following the distributions of the Asterias Series A common stock by Geron to its stockholders, BioTime will own, including the shares of Asterias Series B common stock that BioTime presently owns, approximately 71.6% of the outstanding Asterias common stock, the Geron stockholders will own approximately 21.4% of the outstanding Asterias common stock and the private investor will own approximately 7.0%, of the outstanding Asterias common stock.

BioTime will also receive warrants to purchase 3,150,000 shares of Asterias Series B common stock and the private investor will receive warrants to purchase 350,000 shares of Asterias Series B common stock (the "Asterias Warrants"). The Asterias Warrants will have an exercise price of $5.00 per share and a term of three years. The exercise price per share and number of shares that may be purchased upon the exercise of the Asterias Warrants will be subject to adjustment in the event of any Asterias stock split, reverse stock split, stock dividend, reclassification of shares and certain other transactions.

The Asterias Series A and Series B common stock will be identical in most respects, however, Asterias will be entitled to make certain distributions or pay dividends, other than stock dividends, on its Series A common stock, without making a distribution or paying a dividend on its Series B common stock. The Asterias Series B common stock may be converted into Asterias Series A common stock, on a share for share basis, at Asterias' election, only after Geron distributes to its stockholders the Asterias Series A common stock issued under the Asset Contribution Agreement and Asterias subsequently distributes to the Asterias Series A common stock holders the 8,000,000 BioTime warrants that Asterias will receive from BioTime under the Asset Contribution Agreement.

Closing of the asset contribution transaction is subject to certain negotiated conditions, including: the effectiveness of registration statements under the Securities Act of 1933 filed by BioTime and Asterias, and the approval by BioTime shareholders of the issuance of BioTime shares and warrants in the transaction, and an amendment of BioTime's Articles of Incorporation to increase its authorized capital stock (the "Shareholder Proposals").

Closing of the cash contribution by the private investor is also subject to certain negotiated closing conditions, including the closing of the asset contribution transaction.

BioTime will be required to pay Geron a termination fee of $1.8 million in certain circumstances if the Asset Contribution Agreement is terminated if (a) the BioTime board of directors withdraws its recommendation to BioTime shareholders to approve the Shareholder Proposals, (b) certain BioTime directors materially breach the Support Agreements under which they and certain of their affiliates have agreed to vote their BioTime shares in favor of the Shareholder Proposals, or (c) BioTime's shareholders do not vote to approve the Shareholder Proposals.