FIG. 4.

Southern blot analysis of G418-resistant HT-1080 clones. Genomic DNAs from four representative G418-resistant clones were isolated on 1% agarose gels without digestion or after digestion with HindIII, BamHI or BglII, and probed for neo sequences. The positions of size standards and the expected 4.1-kb BglII vector fragment are shown to the left and right of the panels, respectively. The predicted structure of an integrated provirus is shown below the panels with the locations of HPRT intron sequences (thick line), HPRT exon 3 (dark boxes), MVM right (R)- and left (L)-terminal palindromes, TK promoter (T), neo gene, pA sites, and relevant restriction sites (BamHI, B; BglII, Bg; HindIII, H) indicated.