In order to detect the low numbers of hepatitis A viral (HAV) particles which may potentially be present in food and cause a serious illness, an original procedure which combines immunomagnetic separation and PCR is described. The use of streptavidin magnetic beads coated with biotinylated human anti-HAV IgG allows virus capture and the removal of the RT-PCR inhibitory compounds which usually are present in shellfish extracts. Following immunomagnetic capture, the separated HAV were lysed, the beads discarded, and the supernatant containing the viral RNA subjected to the RT-PCR protocol. Levels of HAV ranging from 10 to 10(5) pfu were successfully detected in artificially contaminated samples of shucked American oyster (Crassostrea virginica).