Note 2 - Business Combinations (Details) (USD $)	3 Months Ended		12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	May 31, 2013	May 31, 2012
Note 2 - Business Combinations (Details) [Line Items]
Business Combination, Contingent Consideration, Liability	$ 3,251,000		$ 4,504,000	$ 4,504,000
Business Combination, Contingent Consideration Arrangement, Fair Value Disclosure	4,400,000
Business Combination, Acquisition Related Costs	(1,320,000)
	67,000		104,000
Revenue, Net	96,044,000	85,154,000
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	(12,395,000)	(17,109,000)
LIFECODES [Member]
Note 2 - Business Combinations (Details) [Line Items]
Revenue, Net	11,300,000
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	(1,700,000)
LIFECODES [Member]
Note 2 - Business Combinations (Details) [Line Items]
Business Combination, Consideration Transferred	86,200,000
Payments to Acquire Businesses, Gross			87,300,000
Business Acquisition, Due From Seller	1,100,000
Business Combination, Contingent Consideration Arrangement, Fair Value Disclosure	4,400,000
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	1,200,000
Business Combination, Acquisition Related Costs	1,300,000
	100,000
Maximum [Member] | LIFECODES [Member]
Note 2 - Business Combinations (Details) [Line Items]
Business Combination, Contingent Consideration, Liability	$ 10,000,000