The genome profiling method can be applied for species identification of biological materials collected at crime scenes.

BACKGROUND: Various biological materials unrelated to humans are found at crime scenes and it is often important to elucidate the origin of these materials. A genetic locus common to several species is conventionally PCR-amplified with universal primers to identify species. However, not all species can be identified using a single locus. In this study, DNA from 13 commonly handled taxa was analyzed to identify species by a genome profiling (GP) method, which involves random PCR and temperature gradient gel electrophoresis. RESULTS: In a clustering analysis, we successfully obtained a single cluster for each species. CONCLUSION: The GP method is cost-effective and does not require advanced techniques and knowledge in molecular biology. The random sampling of the whole genome using multiple primers provides substantial genomic information. Therefore, the method is effective for classifying a wide range of species, including animals, plants, and insects, and is useful for crime scene investigations.

Comparison between Temperature Gradient Gel Electrophoresis of Bacterial 16S rDNA and Diatom Test for Diagnosis of Drowning.

When a body is discovered in water, it is difficult to conclude whether the cause of death was drowning, even today. Although diatom testing by the digestive method is classical, we hypothesized that aquatic bacteria, as well as diatoms, might be detected in drowned bodies, and conducted temperature gradient gel electrophoresis (TGGE)-targeting 16S rDNA. DNA was extracted from the site water, and from heart blood and liver samples from 27 bodies concluded as drowning deaths by autopsy and subjected to TGGE after amplification of 16S rDNA by polymerase chain reaction. We observed whether the feature point of each 16S rDNA from the site water and blood or liver samples matched. Considerably higher correspondence was observed in drowned bodies, and the rate was higher than that achieved with the digestive method. Moreover, TGGE is safer than the digestive method. Our study suggests that this method can aid diagnosis of drowning.