Impact of delay to cryopreservation on RNA integrity and genome-wide expression profiles in resected tumor samples

Using Illumina HumanHT-12 v3 Expression BeadChips, providing a genome-wide coverage of over 24,000 genes, we have analysed gene expression variation in samples of 3 hepatocellular carcinomas (HCC) and 3 lung carcinomas (LC) cryopreserved at times up to 2 hours after resection. Total RNA obtained 3 frozen Hepatocellular Carcinomas and 3 Lung Carcinomas cryopreserved at 5 min, 15min, 30min and 120min after resection. Tissue samples from the center and the peripheral of the tumours were frozen for each time point.