Instructions with the oncolumn DNase I digestion. The RNA was quality checked by agarose gel electrophoresis and quantified by spectrometry (NanoDrop-1000).Cortisol, weight and hematocrit analysesCortisol levels in plasma were tested by immunoassay of 20 l samples (ParameterTM, R D Systems). Samples were run in duplicate, and a standard curve and interplate calibrator sample was run on each plate.