PCR-RFLP of pal and detection of its gene product, PAL, from clonally diverse A. actinomycetemcomitans strains. Panel A: Agarose gel electrophoresis of the PCR products shows amplicons with the expected size of pal (425 bp) for each strain. Panels B and C: Agarose gel electrophoresis of the purified PCR amplicons digested with DdeI and BspMI, separately. Panel D: immunoblot analysis of the A. actinomycetemcomitans whole cell protein preparations using anti-AaPAL peptide antiserum shows the expected 17-kDa signal for each strain. Lanes 1 through 12 strain identification (serotype; genotype): ATCC 29523 (a; 1), SA5002 (a; 1), ATCC 43718 (b; 2), SA5003 (b; 8), ATCC 33384 (c; 3), SA5005 (c; 3), SA5001 (d; 5), SA5007 (d; 22), SA5008 (e; 6), SA5011 (e; 20), CU1000R (f; nd*), SA5022 (f; 19) and standards (S). *nd: not determined.