Oligonucleotides containing degenerate bases. Synthesis and uses

Type-specific detection of echovirus 30 isolates using degenerate reverse transcriptase PCR primers

Following an approach used to specifically identify polioviruses and enterovirus 71, we have developed reverse transcriptase (RT) PCR primers containing mixed-base residues or deoxyinosine at positions of codon degeneracy. These primers permit specific RT-PCR amplification of echovirus 30 (E30) sequences by targeting sites that encode conserved amino acid motifs within the major capsid protein, VP1. All 221 E30 strains tested, isolated in 16 countries over a 44-year period, yielded the predicted 158-bp PCR product. No specific products were obtained by PCR assays containing templates from any of the other 63 EV serotypes. Inosine-containing degenerate primers may be widely applicable to the identification of echovirus serotypes by PCR.