Biological stability of mRNA isolated from human postmortem brain collections

RNA isolated from frozen human postmortem brain tissue was evaluated for its utility in molecular biological studies. Samples varying in postmortem interval, delay period before freezing, and long-term freezer storage were analyzed. It was found that storage of human postmortem brain at -70 degrees C for more than 5 years may compromise its use for oligo-dT primed library construction and in vitro expression studies. Although biological competency of the messenger RNA may be affected by long-term freezer storage of human brain, enough full-length or partial transcripts remained for amplification by the polymerase chain reaction. We conclude that human postmortem brain collections will continue to be valuable resources for the study of gene expression and isolation of nucleotide sequences.