The effect of extraction methods. The kind of organ samples and the examination delay on the DNA yields and typing.

Abstract

This study investigated the effect of DNA extraction methods, examination delay and the kind of organs samples to the DNA yields and typing. Thirty autopsy cases with postmortem period less than 12 hours were used as the sample resources. The DNA was successfully extracted from cerebral cortex, liver, spleen, lymph nodes, kidney, psoas muscle and prostate gland by Bar and Kirby methods. The spectrophotometric measurement showed that the spleen, lymph nodes, kidney and liver provided more DNA rather than the other organs. The agarose gel electrophoresis showed that the majority of the samples had High Molecular Weight-DNA (HMW-DNA) with variable degree of degradation. All of these DNA were successfully typed on the D1S80 locus using the PCR according to Kasai method. The spleen samples were collected from the same cases and stored at -20 degrees C for 1 to 6 weeks before the DNA extraction was performed. The analysis of the DNA extracted from these samples showed that the DNA yields and typing did not change significantly among the samples with examination delay up to 6 weeks after the sample collection. The comparison between the Bar and Kirby methods showed that the Kirby method resulted in more DNA yields with the same purity of DNA, but less HMW-DNA compared with Bar method.