Agarose gel showing PCR-amplified products of the 16S rRNA, mecA, and nuc genes. Lanes 1 and 9, 100-bp DNA ladder. Lane 2, MRSA, showing all three amplification products (16S at 798 bp, mecA at 533 bp, and nuc at 270 bp). Lane 3, MSSA, with only the 16S and nuc products. Lane 4, coagulase-negative, methicillin-resistant staphylococci with 16S and mecA products only. Lane 5, coagulase-negative, methicillin-sensitive staphylococci, showing only the 16S product. Lane 6, MRSA S. aureus ATCC 43300 control. Lane 7, MSSA S. aureus ATCC 29213 control. Lane 8, reagent control.