Southern blot and PCR analyses of the CEM-Tk clones.

Genomic DNAs were digested with the SacI restriction enzyme. Southern blots were hybridized with Tk1 (A) and NGFR (B) specific probes. PCR amplification of the HSV-Tk gene sequence of SFCMM3 provirus (fragment 2, HTK4⁺ and HTK2⁻; 1020 bp) is shown (C).