Preliminary Study on Species Identification for Mixed Blood Stain by Multiplex Amplifying mtDNA-HVI and Cyt b Fragments

Objective To explore species identification for blood strain of human and animal mixed origin through multiplex amplifying mtDNA-HVI and Cyt b fragments.Methods DNA was extracted from blood stains of human,bovine,swine,canine,rabbit,fish,chicken and mouse origin by using the chelex-100 method.Subsequently,duplex PCR reaction was carried out with two sets of primers targeting at mtDNA-HVI and Cyt b fragment respectively,and the amplified products were detected by agarose gel electrophoresis.Results A 279 bp mtDNA-HVI fragment and a 358 bp Cyt b fragment were detected from the human DNA sample when its DNA content is 3.13ng or more,and the former was brighter than the latter.For the animal DNA sample,however,only the 358 bp fragment was observed.Both fragments were also observed from the mixed sample of human and animal DNA when there was 25ng animal DNA and 3.13ng or more human DNA,but the 358 bp fragment was much brighter.Conclusion It suggested that the sample was a mixture of human and animal when both 279 bp and 358 bp bands were observed and the latter was much brighter than the former.