A sensitive method for the detection of murine C-type retroviruses.

A RT-PCR assay was developed for group-specific detection of murine C-type retroviruses using a nested set of degenerated primers. To distinguish exogenous viruses from related, but silent endogenous viruses, a DNAse I pretreatment of supernatants is applied. This is followed by a heat inactivation/denaturation step. The PCR method is ultrasensitive. which enables the detection of 100 attogram of MoMuLV proviral DNA or up to 1-10 infectious mouse C-type retroviruses in 10 microl supernatant of infected cells. The high specificity of the method allows the differentiation between mouse C-type retroviruses and related retroviruses of the A, B, and D type and C-type retroviruses found in other species. It serves as a valuable tool for the screening of animal cell cultures for contaminations with mouse retroviruses, e.g. hybridomas or recombinant cell lines producing foreign proteins.