Fecal samples were obtained from children with gastroenteritis, from the Children's Hospital ward at Uppsala Academic Hospital. Samples were handled anonymously according to the rules of the ethical committee at the Academic Hospital. The study used samples that were positive in a rotavirus antigen detection test; 100 ml of the sample was diluted in 900 ml 1Â TE buffer. After centrifugation, 400 ml was added to a lysis buffer and total nucleic acid was extracted as described by the manufacturer (easyMag Õ , bioMe´rieux). The samples were eluted in 110 ml buffer and stored at À70 C.