FIG. 2.

PCR analysis of phage nucleic acid preparations of V. cholerae strains carrying the TCP island. Preparations from various strains were tested by PCR for tcpA (lanes 4 to 6) and ctxA (lanes 7 to 9). The following V. cholerae strains were tested: lanes 4 and 7, AL-11089; lanes 5 and 8, AL-12077; lanes 6 and 9, P-27457. As positive controls, lanes 1 and 2 contained PCR assay mixtures from assays for tcpA in which chromosomal DNA templates from El Tor strain G-755 and classical strain 569B, respectively, were used. Lane 3 contained the tcpA PCR product of the chromosomal DNA template from strain Env-37, which lacks the tcpA gene. The numbers on the right indicate the positions of bands derived from a 1-kb DNA ladder (Invitrogen) used as molecular size markers.