Effects of Se status on antioxidant enzymes. (A) 50 μg of cellular proteins extracted from Vero and SK-N-SH cells grown in control, Se- and Se+ media at days 7 and 10 post-induction of Se deficiency were separated on PAGE, transferred onto nitrocellulose membranes and immunoblotted with antibodies specific to catalase, CuZnSOD and MnSOD. Equal loading of protein was validated by re-blotting the same membranes with anti-β-actin. The data is representative of three independent experiments. (B) Increase in the expression of MnSOD in Se- and Se+ Vero cells was confirmed by qRT-PCR. cDNA template was synthesized from total RNA extracted from control, Se- and Se+ Vero cells at days 3, 7 and 10 post-induction of Se deficiency as described in the materials and methods and subjected to qRT-PCR using primers specific for MnSOD and β-actin. Changes in the levels of MnSOD transcripts in Se- and Se+ Vero cells were first normalized to β-actin and then the fold-change as compared to controls was calculated. Data are reported as mean ± SD of triplicate experiments.