The invention discloses compositions comprising nucleic acid(s) for rapid detection, identification, differentiation, and/or diagnosis of certain Influenza virus A subtypes, e.g., H1N1, H3N2 and A(2009 H1N1)pdm, and methods of use thereof, e.g., Short-run RT-PCR, including an RT-PCR assay kit, comprising the disclosed composition(s).