Quality and quantity of DNA in cadavers' serum

We investigated the quality and quantity of DNA in sera obtained from 16 cadavers who were left at room temperature or placed in a refrigerator for cadavers within 3 days of their death. The causes of death were as follows: asphyxia, 4; hemorrhage, 4; fire, 3; cold, 1; subdural bleeding, 1; sepsis, 1; cerebral contusion, 1; and pulmonary thromboembolism, 1. When examined using agarose gel electrophoresis, the samples from the victims who died from sepsis and pulmonary thromboembolism exhibited smear patterns, while the other samples exhibited ladder patterns. The size of each band was an integer multiple of approximately 180 bp, considered to be characteristic of apoptosis. The DNA concentration in the cadavers' sera ranged from 3.0 to 258.9 ng/ml. DNA types (D1S80, HLADQA1, TH01, and PM) were determined for all the samples except for the sample from the victim who died from sepsis. The detected types were the same as those obtained from paired bloodstain samples, except for in the asphyxia victim. D1S80 typing of the serum sample from the asphyxia victim showed the loss of the longer allelic hetero-band. These results suggest that the quantity of DNA in serum from cadavers is sufficient for DNA typing, but that the degradation of DNA may proceed quickly, depending on the temperature of the area in which the cadaver is left as well as the pathological conditions that the victim had experienced.