FIG. 5.

RT activity released from infected CP cells. RT activity was tested by PERT assay on 10-fold dilutions of 33-fold-concentrated supernatant from infected CP cells (passage 12) or on equivalently concentrated supernatant from CP cells infected with heat-treated JSRV₂₁ at the same passage. Southern blot hybridization with an MS2-specific probe was used for PCR product detection. Note the presence of the specific MS2 band only in the JSRV₂₁-infected cells. Controls: +, a PERT reaction with purified Moloney murine leukemia virus RT (10⁻⁴ U); −, a PERT reaction with buffer A alone.