FIG. 2.

RT-PCR analysis of DNase-treated RNA extracted from P. gingivalis. Total RNA was extracted from W83 grown to mid-log phase (OD₆₀₀ of 0.3 to 0.4) using a Qiagen RNeasy midi kit. Samples (1 μg) were subjected to RT-PCR (Access RT PCR system; Promega). Lanes: A, Promega kanamycin positive control RNA; B, intragenic primers for recA (P2 and P3 Table 2; Fig. 1); C, forward primer from recA and reverse primer from the downstream gene (P2 and P5 (Table 2; Fig. 1); D, 1-kb ladder. Expected sizes of the transcripts are 0.323, 0.86, and 1.4 kb for the positive control, recA, and recA/downstream genes, respectively. Sizes of the PCR products are given at the left.