The Viral Stool Panel II RT-PCR is a multiplex real-time PCR assay for the direct, qualitative detection and differentiation of rotavirus RNA, adenovirus 40/41 DNA, and astrovirus RNA in human stool samples. Detection takes place in one-step real-time RT-PCR format where the reverse transcription (RT) and the subsequent PCR takes place in the same reaction tube. The isolated RNA is transcribed into cDNA using a reverse transcriptase. Subsequently amplification of the gene fragments specific for rotavirus (NSP3), adenovirus 40/41 (Hexon), and astrovirus (CAP; capsid protein) occurs if present. The amplified targets are detected with hydrolysis probes, which are labeled at one end with a quencher and at the other end with a fluorescent reporter dye (fluorophore). In the presence of a target, the probes hybridize to the amplicons. During the extension step, the Taqpolymerase breaks the reporter-quencher proximity. The reporter emits a fluorescence signal which is detected by the optical unit of a real-time PCR instrument. The fluorescence signal increases with the quantity of formed amplicons. The Viral Stool RT-PCR Panel II assay contains an Internal Control RNA (ICR) as an internal control of the sample preparation procedure and to determine possible PCR inhibition.