Figure 3: Expression of β-lactamase-related genes. PCR showing the expression of blaZ, blai, and blaR1 of MRSA exposed to various concentrations of rhein alone or in combination with 31.25 μg/mL oxacillin. 16s rRNA was used as a loading control and expression levels were normalized to 16s rRNA levels. Different letters (a-d) indicate significant differences at P<0.05, based on analysis of variance followed by the Scheffe's test for multiple comparisons. Values are presented as mean±SD.