The amplified blaz gene (833 bp) of S. aureus for detection of penicillin resistance recovered from multidrug resistant S. aureus (MDR) isolates. Lane L: Molecular marker; Lane P: Positive control; Lane N: Negative control; Lane 1, 4, 5: negative isolates for resistance to penicillin; Lane 2 and 3: positive isolates for resistance to penicillin