FIG. 1.

Gel analysis of PCR-amplified toxin gene sequences. The individual toxin gene products were characterized by comparison with standard molecular size markers. Lane 1, SEC; lane 2, 100-bp ladder; lane 3, SEA; lane 4, SEB; lane 5, SED; lane 6, SEE. These were combined to create a standard set of toxin gene products (lane 14). Genomic DNA was prepared from toxigenic strains of S. aureus and analyzed using the multiplex PCR assay, including primer SEC for gene sec (lanes 7 to 14). The S. aureus strains used were as follows: lane 7, F287 (SEA); lane 8, NCTC 10654 (SEB); lane 9, NCTC 10655 (SEC); lane 10, NCTC 10656 (SED); lane 11, FRI326 (SEE); lane 12, NCTC 10657 (SEA and SEB); and lane 13, NCTC 10652 (SEA and SED). The additional 790-bp product produced by the SA-D–SA-U primer pair is visible in lane 5.