Fig. 1.

Typing of staphylococcal SAg by multiplex PCR. Seven staphylococcal SAg genes (SEA-SEE, TSST-1 and ETA) can be typed in three separate reactions using this multiplex PCR protocol. Typing of the genes makes use of the fact that the SAg-specific primers yield different amplicon sizes. Thus, SEA, SEC and TSST-1 (lane 2), SED and SEE (lane 3) and SEB and ETA (lane 4) can be detected in the same reaction. Additionally, the S. aureus specific nuclease-a gene was co-amplified in order to confirm the strain species. To illustrate the method, total DNA from S. aureus strains carrying one of the genes encoding for the SAg SEA-SEE, TSST-1 or ETA, respectively, were mixed, thus creating an artificial positive control. The100 base pair ladder was used as a size marker.