Summary of significant accounting policies (Tables)

12 Months Ended

Jul. 31, 2012

Schedule Of Segment Revenue And Revenue Percentage [Table Text Block]

The following tables of the Clinical Lab segment’s net revenues and revenue percentages by revenue category:

	2012					Years ended July 31, 2011					2010
Revenue category			(in %)					(in %)					(in %)
Medicare	$	12,658		21		$	11,856		22		$	11,158		25
Third-party payers		29,616		50			24,335		46			19,534		44
Patient self-pay		11,895		20			11,554		22			8,758		20
HMO’s		5,234		9			5,017		10			4,728		11
Total	$	59,403		100	%	$	52,762		100	%	$	44,178		100	%

Schedule Of Accounts Receivable By Segment [Table Text Block]

The following is a table of the Company’s net accounts receivable by segment.

	July 31, 2012					July 31, 2011
Net accounts receivable by segment			(in %)					(in %)
Clinical Labs (by billing category)
Medicare	$	1,270		16		$	1,434		19
Third party payers		3,478		45			3,087		40
Patient self-pay		2,655		35			2,865		37
HMO’s		330		4			314		4
Total Clinical Labs		7,733		100	%		7,700		100	%
Total Life Sciences		6,402					7,545
Total accounts receivable	$	14,135				$	15,245

Changes in the Company’s allowance for doubtful accounts are as follows:

	July 31, 2012			July 31, 2011
Beginning balance	$	3,488		$	2,839
Provision for doubtful accounts		5,104			4,431
Write-offs		(5,319	)		(3,782	)
Ending balance	$	3,273		$	3,488

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

The following table sets forth the computation of basic and diluted net loss per share for the years ended July 31:

	2012			2011			2010
Numerator:
Net loss	$	(39,269	)	$	(12,960	)	$	(22,233	)
Denominator:
Weighted-average common shares outstanding- Basic		38,798			38,357			38,001
Add: effect of dilutive stock options and restricted stock		—			—			—
Weighted-average common shares outstanding - Diluted		38,798			38,357			38,001
Net loss per share
Basic and diluted	$	(1.01	)	$	(0.34	)	$	(0.59	)

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

The following table sets forth the amount of expense related to share-based payment arrangements included in specific line items in the accompanying statement of operations for the years ended July 31:

	2012		2011		2010
Cost of clinical laboratory services	$	10	$	10	$	12
Research and development		4		14		14
Selling, general and administrative		705		1,025		1,144
	$	719	$	1,049	$	1,170