4.4. cDNA Synthesis and qPCR

Five hundred nanograms of total RNA were used for cDNA synthesis using the Applied Biosystems™ High-Capacity RNA-to-cDNA™ Kit (Cat.4388950, (Thermo Fisher Scientific, Waltham, MA, USA), following the manufacturer’s instructions. The resulting cDNA was used to perform qPCRs using the TaqMan™ Gene Expression Master Mix accordingly to the user guide directives. GAPDH was used as internal control to normalize gene expression levels. For the arsenite experiments, cDNA measurements using Qubit were used as normalizer, as arsenite exposure significantly alters the expression of a panoply of genes, including housekeeping genes that for that reason are not adequate to normalize qPCR data. The reaction was carried out in the Applied Biosystems 7500 Real-Time PCR System.