Warranties

The Company generally provides a one-year warranty on instruments. Additionally, the Company provides a warranty on its consumables through the expiration date, which generally ranges from six to twelve months after the manufacture date. At the time revenue is recognized, the Company establishes an accrual for estimated warranty expenses based on historical experience as well as anticipated product performance. The Company periodically reviews the adequacy of its warranty reserve and adjusts, if necessary, the warranty percentage and accrual based on actual experience and estimated costs to be incurred. Warranty expense is recorded as a component of cost of product revenue. Estimated warranty expenses associated with extended maintenance contracts for systems are recorded as a cost of service and other revenue as incurred.

Changes in the Company’s reserve for product warranties from January 1, 2012 through April 1, 2012 are as follows (in thousands):



Balance as of January 1, 2012	$	11,966
Additions charged to cost of revenue	4,111
Repairs and replacements	(4,206		)
Balance as of April 1, 2012	$	11,871