Note 8 - Revenue - Revenue by Major Source (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenues	$ 6,513	$ 6,087	$ 13,021	$ 11,800
Testing [Member]
Revenues	5,480	5,367	11,204	10,416
Shipping/Collection (Hair) [Member]
Revenues	1,001	680	1,751	1,295
Other Revenue [Member]
Revenues	$ 32	$ 40	$ 66	$ 89

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