Detection of MuLV in other laboratory cell lines. (A) Nonquantitative RT-PCR detects MuLV-related virus in several laboratory cell lines. Lane M, molecular size marker; lane NTC, no-template control. (B) Quantitative RT-PCR analysis of a larger panel of B-cell lines shows the presence of MuLV-related virus in DG75, Ramos, P3HR1 Cl.13, and JY cells.