Effect of blood storage conditions on DNA repair capacity measurements in peripheral blood mononuclear cells

Due to the great number of genes involved in DNA repair and the interactions among the pathways responsible for the repair of different types of DNA damage, there is an increasing need for simple and reliable approaches to phenotypically assess DNA repair capacity (DRC). The use of peripheral blood mononuclear cells (PBMCs) in DRC assays is particularly useful for human monitoring studies. However, in such studies it is not always possible to collect and process samples on the same day as the blood is taken. We performed a genotype-phenotype correlation study on DRC on 225 healthy subjects. Due to the large number of blood samples to be processed, PBMCs were either isolated and cryopreserved on the same day of blood collection (day 1) or on the following day after 24h blood storage at room temperature (day 2-RT). Samples processed in different days showed a significant difference in the DRC evaluated as 8-oxoguanine glycosylase activity (OGG assay) in cell extracts (p