Cash and cash equivalents include bank demand deposits, certificates of deposit, investments in debt securities with maturities of three months or less when purchased, and an interest in money market funds which invest primarily in U.S. government obligations. Investments in marketable securities consist of equity securities and corporate or government debt securities that have a readily ascertainable market value and are readily marketable. We report these investments at fair value. We designate all cash equivalents and marketable securities as available-for-sale, with unrealized gains and losses included as a component of equity.

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value

At September 30, 2012
Money market funds	$	1,041	$	—	$	—		$	1,041
U.S. corporate debt securities		34,666		2		—			34,668
Debt securities issued by U.S. government and U.S. government agencies		89,224		22		(1	)		89,245
Marketable equity securities		16		15		—			31

Total	$	124,947	$	39	$	(1	)	$	124,985

At December 31, 2011
Money market funds	$	4,469	$	—	$	—		$	4,469
U.S. corporate debt securities		32,830		—		(1	)		32,829
Debt securities issued by U.S. government and U.S. government agencies		72,901		14		(2	)		72,913
Marketable equity securities		2,726		—		(907	)		1,819

Total	$	112,926	$	14	$	(910	)	$	112,030

The available-for-sale securities are classified on the balance sheet as follows (in thousands):

	Fair Value

	September 30, 2012		December 31, 2011
Amounts included in cash and cash equivalents	$	21,889	$	23,767
Marketable securities, current		103,065		86,444
Marketable securities, non-current		31		1,819

Total	$	124,985	$	112,030

At September 30, 2012, all of our debt securities were due in one year or less based on their contractual maturities.

In the three and nine month periods ended September 30, 2012 and 2011, realized gains and losses calculated using the specific identification method were insignificant.

We evaluate investments with unrealized losses to determine if the losses are other than temporary. In making this determination, we consider the financial condition and near-term prospects of the issuers, the magnitude of the losses compared to the investments' amortized cost, changes in the credit quality of the issuer, the length of time the investments have been in an unrealized loss position, and whether it is more likely than not that we will hold the investment for a period of time sufficient for a recovery of our cost basis.

As of December 31, 2011, we held 2,384,211 shares of AVI BioPharma, Inc. ("AVI") common stock. In July 2012, AVI changed its name to Sarepta Therapeutics, Inc. ("Sarepta") and effected a six for one reverse stock split. In September 2012, we sold all of our shares of Sarepta for $5,384,000, resulting in a net gain on sale, after payment of broker commissions, of $2,606,000.

Equity investments in securities without readily determinable fair value, which consist of investments in privately held companies, are carried at cost. As of December 31, 2011, we held one such non-marketable security with a carrying amount of $500,000, which has been included in other assets in the condensed consolidated balance sheets. We periodically review this investment and evaluate whether an impairment has occurred. We monitor the liquidity and financing activities of the issuer of this security and evaluate, among other factors, the financial condition and business outlook of the issuer, including key operational and cash flow metrics and current market conditions, as well as our intent and ability to retain the investment. During the quarter ended September 30, 2012, based on the current financial status and information received from the issuer, we determined that the value of our investment was impaired, and recorded an other than temporary decline in value of $485,000.

During the quarter ended September 30, 2012, we acquired an investment of 681,632 shares of Series A preferred stock, representing less than 20% ownership, of a privately held company valued at $2.20 per share, for a total investment of $1,500,000. This amount is included in other assets in the condensed consolidated balance sheets. In exchange for acquisition of these shares, we contributed fixed assets and other intellectual property from our Utah laboratory location with a net book value of $924,000, resulting in the recognition of a gain on disposition of assets of $576,000.