Total RNA (200 ng) was used as starting material for the cDNA preparation. First and second strand cDNA synthesis, the in vitro transcription reaction to generate cRNA and the second round of cDNA synthesis was performed using the Ambion® WT Expression Kit according to the manufacturer’s instructions. Biotin labelling was performed using the Terminal Labeling Kit (Affymetrix) according to the manufacturer’s instructions. Following the in vitro transcription reaction, the unincorporated nucleotides were removed using RNeasy columns (Qiagen).
