Note 9 - Revenue - Revenue by Major Source (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenues	$ 4,728	$ 5,537	$ 10,085	$ 11,396
Testing [Member]
Revenues	3,938	4,614	8,478	9,552
Shipping/Collection (Hair) [Member]
Revenues	764	897	1,549	1,795
Other Revenue [Member]
Revenues	$ 26	$ 26	$ 58	$ 49

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

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+ Details