TABLE 1.

Microbiological parameters tested during the two oyster trials^a

Date of trial	Laboratory	Detected virusb
		ADV	EV	HAV	NLVI	NLVII
November 1999	1	+	+	+	+	−
	2	+	+	−	−	−
	3	+	−	−	−	+
	4	+	+	+ (weak)	+	+
January 2000	1	+	+	+	+	+ (weak)
	2	+	−	NT	+	−
	3	−	−	−	+	+
	4	−	+	−	+	−

^aLaboratories 1, 2, and 4 applied method 1 and laboratory 3 applied method 2 as described in Materials and Methods.

^bNT, not tested; +, positive results by PCR; −, negative result by PCR.