Typing and subtyping of influenza viruses and respiratory syncytial viruses by multiplex RT-PCR

We developed a series of oligonucleotide primers capable of detecting, typing, and subtyping influenza virus type A (H1 and H3) and type B and respiratory syncytial viruses types A and B. RNAs were isolated from culture fluid or clinical specimens, and cDNA synthesis and PCR were carried out with mixtures of primers specific to each virus. Amplified products were detected by ethidium bromide staining of amplified products after agarose gel electrophoresis. For each virus, five amplified products of different sizes could be distinguished on agarose gels. Multiplex RT-PCR can also be used to detect more than one viral template in the same reaction mixture, allowing identification of multiple strains in the same specimen.