Total RNA was extracted using TRIZOL Reagent (Cat#15596-018¡ALife technologies, Carlsbad, CA, US)following the manufacturer's instructions and checked for a RIN number to inspect RNA integrity by an Agilent Bioanalyzer 2100 (Agilent technologies, Santa Clara, CA, US). Qualified total RNA was further purified by RNeasy micro kit (Cat#74004, QIAGEN, GmBH, Germany) and RNase-Free DNase Set (Cat#79254, QIAGEN, GmBH, Germany).
Label
biotin
Label protocol
Total RNA were amplified, labeled and purified by using GeneChip 3'IVT Express Kit (Cat#901229, Affymetrix, Santa Clara, CA, US) followed the manufacturer's instructions to obtain biotin labeled cRNA.
Hybridization protocol
Array hybridization and wash was performed using GeneChipR Hybridization, Wash and Stain Kit (Cat#900720, Affymetrix, Santa Clara, CA, US)in Hybridization Oven 645 (Cat#00-0331-220V, Affymetrix, Santa Clara, CA, US)and Fluidics Station 450 (Cat#00-0079, Affymetrix, Santa Clara, CA, US) followed the manufacturer's instructions.
Scan protocol
Slides were scanned by GeneChipR Scanner 3000 (Cat#00-00212, Affymetrix, Santa Clara, CA, US) and Command Console Software 3.1 (Affymetrix, Santa Clara, CA, US) with default settings.
Data processing
Robust Multichip Average (RMA) method by R was used for data processing and normalization