ABSTRACT
Objective Blood trace and extraction is the important premising for forensic medicine appraisal reliability, this paper puts forward the blood trace and extraction method of using pyramidon. Methods Using pyramidon and benzidine to treat diluted fresh blood, and using Chelex-100 reagent treatment after the DNA in blood samples, and then applying the technology of PCR-STR and fluorescence detection test sample STR typing, observing the STR classification results and the detection sensitivity of DNA, comparing the different influence of two method on subsequent DNA - STR inspection. Results The pyramidon method can detect the minimum hemoglobin concentration is 25μg/mL,which was lower than 5μg/mL of the benzidine method. The results showed that the effective typing rate of the benzidine method was 18.09%, which was significantly lower than 96.67% of the method of the pyramidon method. The tail length of the detection group was 52.40±9.21, and the Oliva tail moment was 43.29±4.85%, and the tail intensity was 16.25±2.35, which was significantly higher than that of the pyramidon group (P < 0.01). Conclusions The sensitivity of the pyramidon method is moderate, and the influence of the following STR subtype and the nuclear DNA of the sample is significantly lower than that of benzidine, which can be used in the pre-experiment of blood stain in forensic medicine.
ABSTRACT
Objective To construct a rapid genetic DNA extraction method, with nano magnetic beads, self-designed reagents system and extracting process. Method Part I: DNA extraction from old blood cotton swab sample with self-designed DNA extraction kit, then quantiifed by UV spectrophotometer. The method was further optimized on the preliminary results. Part II: All kinds of difficult DNA sample were tested with optimized kit, to detect the applicability of the kit. Result By improving the experimental condition, the extraction effects of different DNA sample is good, meanwhile, the extraction cost is relatively low.