FIG. 7.—

Direct evidence of PeSL mini-circle independent DNA molecules. Extracted RB49 DNA was filtered through three differing pore-size ultrafiltration membranes, which separate larger molecules (remain in retentate) from smaller ones (flow through the filter). The various fractions were used as templates in normal PCR to detect genomic DNA and inverse-PCR to detect the presence of PeSL192 and PeSL210 mini-circles (as in figs. 4 and 6). Lanes labeled with an “M” contain molecular weight markers, with pertinent sizes indicated. The approximate dsDNA cutoffs (defined as 90% retention) for the membranes are as follows: 30K ≈ 150–300 bp; 300K ≈ 1.5–3 kb; 1000K ≈ 5–10 kb.