DefinePK

Abstract

ABSTRACT The objective of this study was to establish a new compound amplification detection system by using the loci of autosomes and Y chromosomes to achieve the classification of DNA, so as to identify forensic samples. A total of two hundred fifty blood samples were collected from Chelex-100 method and direct amplification method, respectively. Twenty five animal blood samples were used to prepare mixed DNA samples for males and females, and 29 criminal case samples were collected. By being used six color fluorescence labeling technology, gene loci on 21 autosomes and 34 Y chromosomes were detected and directly amplified to establish a composite amplification detection system. The stability, sensitivity, direct expansion feasibility, species specificity, and anti-inhibitor properties of the system should be examined. After being tested Chelex samples and direct expansion samples, the detection system showed good accuracy and stability, and could produce clear and complete the classification of DNA. When the template DNA concentration is ≥ 0.125ng, the detection system can accurately identify all gene loci. When the ratio of male DNA concentration is ≥ 1:4, all loci can be accurately classified. And then by being added to a certain concentration of PCR inhibitors (heme ≤ 150 μmol/L, hemoglobin ≤ 500 μmol/L, humic acid ≤ 10 ng/μL), all loci can be clearly classified. The detection system of compound amplification of autosomal and Y-chromosome loci is suitable for DNA identification in forensic samples. It has good stability in template DNA concentration and inhibitors within a certain range, and can accurately and stably identify multiple loci on the autosomal and Y chromosomes, providing a practical application form for DNA quantitative identification.