Sequence analysis and molecular detection of mouse hepatitis virus using the polymerase chain reaction.

Sequence analysis of the nucleocapsid protein genes of five strains of mouse hepatitis virus (MHV) disclosed that the 3' region of the nucleocapsid protein gene contains highly conserved sequences unique to MHV. We designed a pair of primers to amplify cDNA from such sequences of MHV by using the polymerase chain reaction (PCR). Six isolates of wild-type MHV, as well as prototype viruses, were amplified successfully and detected in ethidium bromide-stained agarose gels. The sequence identity of PCR products was readily verified by confirming target size and a MflI site within the target. The sensitivity of our PCR assay was estimated to be sufficient to detect a single cell infected with MHV. This new approach may permit more sensitive and rapid detection of MHV in biologic materials than current methods such as virus isolation, the infant mouse bioassay, and the mouse antibody production test.