FIG. 2.

Persistence of a 520-bp fragment of pVACMC1 DNA after incubation with fresh, whole saliva for 9 min. PCR amplification of degraded DNA was carried out as described in Materials and Methods, and products were analyzed on a 1.4% (wt/vol) agarose gel. A 1-kb DNA ladder (Gibco BRL), 0.5 to 12.2 kbp, was used.