Аннотация:In the absence of culture methods for noroviruses, detection in foods relies on molecular detection by Reverse Transcription -Polymerase Chain Reaction (RT-PCT) on extracted viral RNA.We have tested four RNA extraction protocols for their sensitivities and robustness to detect norovirus in spiked oysters.One method seemed to be more sensitive than the others using RT seminested-PCR.Not much difference was observed between the four methods by a RT single-PCR approach.Finland