FIG. 3.

Detection of NOR in spiked oyster, lettuce, and strawberry samples. A. NOR virus was spiked in PBS (diamond) or in oyster (triangle) samples at a concentration of 10 RT-PCR units and was concentrated by using PGM-MB. An equivalent amount of NOR virus was spiked into oyster samples, and virus RNA was extracted by the standard RNA extraction method (square). Un-spiked oyster samples were used as negative controls (circle). Similar Ct values for recovery of NOR from PBS and oyster samples suggest that inhibitors are removed by PGM-MB. The presence of inhibitors in oyster samples was confirmed in oyster samples where viral RNA was extracted directly (square). B. NOR virus was spiked into lettuce (diamond) or strawberry (triangle) samples at a concentration of 10 RT-PCR units and was concentrated by using PGM-MB. An equivalent amount of NOR virus was spiked into lettuce (circle) and strawberry (square), and virus RNA was extracted by the standard RNA extraction method as an input control.