The quality of DNA recovered from the archival tissues of atomic bomb survivors is good enough for the single nucleotide polymorphism analysis in spite of the decade-long preservation in formalin.

It is well known that the yield of DNA recovered form tissues preserved in formalin is inversely proportional to the stored duration. How is the quality? We tested the quality of DNA from archival tissues of atomic-bomb survivors stored in formalin for decades with the parameters of gene amplification efficiency by a polymerase chain reaction. All of the DNA extracted from the tissues preserved in formalin for 30 years amplified the 54- and 61-base pairs of the DNA fragments successfully. The direct sequencing of the PCR products confirmed the accurate amplification of the target sequence. A further trial to amplify the longer sequence of 111 base pairs succeeded in 20% of the samples tested. From these results, we propose a new utility of archival samples for the analysis of single nucleotide sequence polymorphism of genes, no matter how long the samples have been preserved in formalin.