10. Stock Option Plans

During 2002, BioTime adopted the 2002 Employee Stock Option Plan (the "2002 Plan"), which was amended in 2004, 2007, and 2009 to reserve additional common shares for issuance under options or restricted stock awards granted to eligible persons. The 2002 Plan expired during September 2012 and no additional grants of options or awards of restricted stock may be made under the 2002 Plan.

During December 2012, BioTime's Board of Directors approved the 2012 Equity Incentive Plan (the "2012 Plan") under which BioTime has reserved 4,000,000 common shares for the grant of stock options or the sale of restricted stock. No options may be granted under the 2012 Plan more than ten years after the date upon which the 2012 Plan was adopted by the Board of Directors, and no options granted under the 2012 Plan may be exercised after the expiration of ten years from the date of grant. Under the 2012 Plan, options to purchase common shares may be granted to employees, directors and certain consultants at prices not less than the fair market value at date of grant, subject to certain limited exceptions for options granted in substitution of other options. Options may be fully exercisable immediately, or may be exercisable according to a schedule or conditions specified by the Board of Directors or the Compensation Committee. The 2012 Plan also permits BioTime to award restricted stock for services rendered or to sell common shares to employees subject to vesting provisions under restricted stock agreements that provide for forfeiture of unvested shares upon the occurrence of specified events under a restricted stock award agreement. BioTime may permit employees or consultants, but not officers or directors, who purchase stock under restricted stock purchase agreements, to pay for their shares by delivering a promissory note that is secured by a pledge of their shares.

BioTime may also grant stock appreciation rights ("SARs") and hypothetical units issued with reference to BioTime common shares ("Restricted Stock Units") under the Plan. An SAR is the right to receive, upon exercise, an amount payable in cash or shares or a combination of shares and cash, as determined by the Board of Directors or the Compensation Committee, equal to the number of shares subject to the SAR that is being exercised multiplied by the excess of (a) the fair market value of a BioTime common share on the date the SAR is exercised, over (b) the exercise price specified in the SAR Award agreement.

The terms and conditions of a grant of Restricted Stock Units will be determined by the Board of Directors or Compensation Committee. No shares of stock will be issued at the time a Restricted Stock Unit is granted, and BioTime will not be required to set aside a fund for the payment of any such award. A recipient of Restricted Stock Units will have no voting rights with respect to the Restricted Stock Units. Upon the expiration of the restrictions applicable to a Restricted Stock Unit, BioTime will either issue to the recipient, without charge, one common share per Restricted Stock Unit or cash in an amount equal to the fair market value of one common share.

As of December 31, 2012, BioTimehad granted to certain employees, consultants, and directors, options to purchase a total of 3,426,301 common shares at exercise prices ranging from $0.5 to $8.58 per share under the 2002 Plan and had granted to certain employees to purchase a total of 255,000 common shares at an exercise price of $3.45 per share under the 2012 Plan. The 2012 Plan has not yet been approved by the shareholders.

On January 1, 2006, BioTime adopted a new accounting pronouncement, which requires the measurement and recognition for all share-based payment awards made to BioTime's employees and directors, including employee stock options. The following table summarizes stock-based compensation expense related to employee and director stock options awards for the years ended December 31, 2012, 2011, and 2010, which was allocated as follows:

	Year Ended December 31,
	2012		2011		2010
All stock-based compensation expense:
Research and Development	$	815,052	$	885,581	$	473,893
General and Administrative		1,028,910		916,832		619,838
All stock-based compensation expense included in expenses	$	1,843,962	$	1,802,413	$	1,093,731

BioTime adopted a new accounting pronouncement using the modified prospective transition method of accounting for options granted on or after January 1, 2006. As of December 31, 2012, total unrecognized compensation costs related to unvested stock options was $3,186,859, which is expected to be recognized as expense over a weighted average period of approximately 5.97 years.

For all applicable periods, the value of each employee or director stock option was estimated on the date of grant using the Black-Scholes Merton model for the purpose of the pro forma financial disclosures in accordance with a new accounting pronouncement.

The weighted-average estimated fair value of stock options granted during the years ended December 31, 2012 and 2011 was $4.13and $4.89 per share, respectively, using the Black-Scholes Merton model with the following weighted-average assumptions:

	Year EndedDecember 31,
	2012			2011

Expected life (in years)		6.35			6.46
Risk-free interest rates		1.06	%		1.85	%
Volatility		98.88	%		106.49	%
Dividend yield		0.0	%		0.0	%

General Option Information

A summary of all option activity under the 1992 Plan, 2002 Plan, and the 2012 Plan for the years ended December 31, 2012, 2011, and 2010, is as follows:

	Options Available for Grant			Number of Options Outstanding			Weighted Average Exercise Price
January 1, 2010		2,087,168			3,477,000		$	1.13
Granted		(245,000	)		245,000			6.75
Exercised (1)		-			(401,410	)		1.56
December 31, 2010		1,842,168			3,320,590		$	1.13
Granted		(560,443	)		560,443			4.89
Exercised		-			(450,660	)		0.50
Forfeited/expired		21,468			(21,468	)		5.60
December 31, 2011		1,303,193			3,408,905		$	2.18
Granted under 2002 Plan		(280,000	)		280,000			4.75
Granted under 2012 Plan		(255,000	)		255,000			3.45
Exercised		-			(98,541	)		2.91
Forfeited/expired under 2002 Plan		-			(164,063	)		5.60
Added by 2012 Plan (2)		4,000,000			-			-
Reduce options ungranted under 2002 Plan(3)		(1,023,193	)		-			-
December 31, 2012		3,745,000			3,681,301		$	1.96

1)	This table excludes 250,000 options which were granted in 2008 outside the 1992 Plan and 2002 Plan, of which 125,000 were exercised in 2009 and the remaining 125,000 were exercised in 2010.

2)	During December 2012, the 2012 Equity Incentive Plan was approved by the BioTime Board of Directors making 4,000,000 common shares available for the grant of options. This plan has not yet been approved by the shareholders.

3)	During September 2012, the 2002 Plan expired.

Additional information regarding options outstanding as of December 31, 2012 is as follows:

				Options Outstanding				Options Exercisable

Range of Exercise Prices		Number Outstanding		Weighted Avg. Remaining Contractual Life		Weighted Avg. Exercise Price		Number Exercisable		Weighted Avg. Exercise Price
				(years)
$	0.50		1,970,400		1.77	$	0.50		1,970,400	$	0.50
	2.30-8.58		1,710,901		4.06		4.43		1,004,007		4.36
$	0.50-$8.58		3,681,301		2.84	$	2.32		2,974,407	$	1.80

During 2011, BioTime's subsidiary, LifeMap Sciences adopted a stock option plan that has substantially the same operative provisions as the BioTime 2002 Stock Option Plan. The LifeMap Sciences stock option plan authorized the sale of up to 8,000,000 shares of its common stock through the exercise of stock options or under restricted stock purchase agreements. During 2012, the LifeMap Sciences stock option plan was amended to reflect a 1 for 4 reverse stock split and a change in plan. As a result, the total number of shares that may be issued under the plan was adjusted to 1,842,269.

During 2010, BioTime's subsidiaries OncoCyte, OrthoCyte, ReCyte Therapeutics, and BioTime Asia adopted stock option plans that have substantially the same operative provisions as the BioTime 2002 Stock Option Plan. The OncoCyte, OrthoCyte and ReCyte Therapeutics stock option plans each authorize the sale of up to 4,000,000 shares of the applicable subsidiary's common stock through the exercise of stock options or under restricted stock purchase agreements. The BioTime Asia stock option plan authorizes the sale of up to 1,600 ordinary shares through the exercise of stock options or under restricted stock purchase agreements. Cell Cure Neurosciences' option plan authorizes the sale of 14,100 ordinary shares through the exercise of stock options.

				Options Outstanding				Options Exercisable

Range of Exercise Prices		Number Outstanding		Weighted Avg. Remaining Contractual Life		Weighted Avg. Exercise Price		Number Exercisable		Weighted Avg. Exercise Price
				(years)
$	0.003-$0.10		5,216,226		6.95	$	0.37		2,790,371	$	0.34
	1.00-1.75		1,042,347		6.01		1.37		212,250		1.01
	2.05		1,550,000		7.43		2.05		681,250		2.05
	27.00-42.02		7,840		7.80		37.35		7,840		37.35
$	0.003-$42.02		7,816,413		6.92	$	0.87		3,691,711	$	0.77

No other options were granted under the other subsidiary Stock Option Plans as of December 31, 2012.