Measurement of Thioredoxin Reductase Levels
We measured serum TrxR levels by using commercial ELISA kit (Bioassay Human TrxR ELISA Kit, Catalog no: E3953Hu). Optical density (OD) on ELISA kit plates was read with a spectrophotometer at 450 nm wavelength (Thermo Scientific- MultiscanGoUV). Working concentrations were calculated using the four parametric logistic (4PL) calibration curve and the values were expressed as ng / mL. The analysis range in the study was 0.05-30 ng / mL and the sensitivity was 0.026 ng / mL. The samples were pre-diluted 8-fold before measurement. The final results were calculated by multiplying with the dilution factor [8].