Impact of RNA integrity and blood sample storage conditions on the gene expression analysis

BACKGROUND: The reliability of RNA sequencing (RNA-seq) output is affected by the quality of RNAs, which is in turn dependent on the quality of samples. Therefore, the purposes of this study were to reconsider the threshold of the RNA integrity number (RIN) and propose a simple and efficient storage scheme of blood samples for RNA-seq. PATIENTS AND METHODS: The RNAs were extracted from blood samples that were stored at different conditions and used for sequencing. The bioinformatic analyses were performed to evaluate the impact of RNA integrity and blood sample storage conditions on the gene expression analysis. RESULTS: Our outcomes showed that the samples with RIN values more than 5.3 scarcely affected the quantitative results of RNA-seq, and the influence of inherent cellular physiological processes on RNA-seq output could be negligible. CONCLUSION: The blood samples stored at 4°C within 7 days with RIN values more than 5.3 were available for RNA-seq.