Patent ID: 7807345

Claim:
A kit for detecting the presence, absence, or quantity of an influenza virus, the kit comprising instructions and a genetically engineered cell that is stably transfected with an isolated recombinant DNA molecule, the isolated recombinant molecule comprising in 5′ to 3′ order: a promoter for a DNA-dependent RNA polymerase; a transcription initiation site for the DNA-dependent RNA polymerase; a DNA sequence encoding an artificial segment comprising a cDNA of a 5′ untranslated region (UTR) of an influenza virus, a reporter gene encoding a polypeptide, and a cDNA of a 3′ UTR of an influenza virus; and a transcription termination site, wherein said promoter, said transcription initiation site, said artificial segment, and said transcription termination site are operably linked, wherein expression of the polypeptide in a cell comprising said recombinant DNA molecule depends upon the presence in the cell of an RNA-dependent RNA polymerase of the influenza virus; wherein the influenza virus is selected from the group consisting of influenza A virus, influenza B virus, and influenza C virus; wherein both the 5′ UTR and the 3′ UTR are from a virus whose presence, absence, or quantity is to be detected in the biological specimen, wherein said cell is susceptible to infection with said influenza virus, and wherein viral proteins PA, PB1, PB2, and NP are absent from said transfected cell.