Evaluation of the suitability of mitochondrial DNA for species identification of microtraces and forensic traces

摘要

The objective of the study was to demonstrate how mitochondrialDNA (mtDNA) can be used to determine thespecies origin of animal microtraces. The study includedpieces of cat and dog hair without the root, a fragmentof cooked chicken bone (0.1g), three goose down samples(0.028 g), a pork swab, a pork scratching (5×5×5mm), and pork lard (0.22 g). DNA was isolated from allof these samples using the method appropriate for theparticular source material. The extracts had DNA concentrationexceeding 5.4 ng/μl with A260/280 purity range of1.14–1.88. Next, the samples were subjected to PCR andreal-time PCR with species-specific primers and primerscomplementary to mitochondrial DNA (mtDNA). Controlreactions based on the amplification of eukaryotic-specificfragment (18S rRNA) were additionally performed.PCR and real-time PCR products for detection of speciesspecificmtDNA were obtained for all templates, whereasduring the detection of eukaryote DNA no product wasobtained for dog and cat hair only. The poor quality ofthe obtained DNA did not prevent the analysis. The resultsshowed that mitochondrial DNA is suitable foridentification of small or highly processed samples, inwhich genomic DNA often cannot be analyzed.