FIG. 4.
Analyses of DNA repair gene mRNAs by quantitative real-time PCR. Total RNA were isolated in triplicate and processed to remove contaminating DNA. The cDNA was synthesized using gene-specific primers. The mRNA levels were determined using quantitative real-time PCR mix containing SYBR green dye. Amplification of 16S rRNA was used as an internal control. The expression level of each gene was determined by the comparative CT method after normalizing with a 16S rRNA control. The mean expression levels ± standard deviations for each gene under different conditions are plotted (using a log2 scale), and the differences in expression were analyzed for statistical significance by performing a paired Student's t test using GraphPad Prism 4.03 software. *, P < 0.05.