3' terminal nucleotide sequence of human astrovirus type 1 and routine detection of astrovirus nucleic acid and antigens.

Human astrovirus type 1 was purified by caesium chloride density-gradient centrifugation and the virus was located using an immunodot blot technique with polyclonal rabbit serum, which reacted with all five serotypes. The virus banded with a density of 1.33 g/ml. RNA was extracted from the purified virus, converted into double-stranded cDNA, using an oligo(dT) primer, and cloned into plasmid and M13 vectors. The sequence of the 3' end of astrovirus RNA adjacent to the poly(A) tract was determined. This sequence showed no significant homology with the equivalent region of other positive-sense RNA viruses. Synthetic oligonucleotide primers were designed to amplify specifically astrovirus type 1 RNA in a polymerase chain reaction.