Effect of refrigeration storage duration of Blood EDTA samples

We have reported the change from overall gene expression to specific genes and pathways involved in the immune cells of blood depending on the storage and handling conditions. The overall gene pattern showed a strong correlation and the prediction of immune cell proportion was conserved under 4℃ refrigeration for up to 48 hours regardless of the RNA extraction kits used. However, after 4 days of refrigeration, the correlation started to decrease. Additionally, the expression of 65 genes increased more than two-fold while the expression of 221 genes decreased less than two-fold within 48 hours of refrigeration. Our data would contribute to the experimental design of basic research and minimizing the bias of the blood RNA-seq results, since the need for RNA-seq continually increases but it it hard to perform blood RNA-seq immediately after every blood collection. Blood EDTA samples were collected from two healthy males and two healthy females, and stored under 4℃ refrigeration from 24 hours to 16 days. We performed gene expression profiling analysis using data obtained from RNA-seq of those blood EDTA samples with different refrigeration storage duration.