RESUMO
This paper reviews the advances of DNA detection on three types of difficult biological specimens including degraded samples, trace evidences and mixed samples. The source of different samples, processing methods and announcements were analyzed. New methods such as mitochondrial test system, changing the original experimental conditions, low-volume PCR amplification and new technologies such as whole genome amplification techniques, laser capture micro-dissection, and mini-STR technology in recent years are introduced.
Assuntos
Humanos , Biomarcadores , Líquidos Corporais/química , DNA/genética , Impressões Digitais de DNA/métodos , DNA Mitocondrial/genética , Medicina Legal/métodos , Genoma Humano , Microdissecção e Captura a Laser/métodos , Repetições de Microssatélites , Técnicas de Amplificação de Ácido Nucleico/métodos , Reação em Cadeia da Polimerase/métodos , Reprodutibilidade dos Testes , Tamanho da AmostraRESUMO
OBJECTIVE@#To assess the application value of laser capture microdissection (LCM) technique for isolating a small number of sperm cells from mixture sample.@*METHODS@#Mixture samples were prepared with sperm cells and vaginal epithelia at different concentrations. Both LCM technique and the differential lysis method were employed to obtain sperm cells from the mixture samples, and DNA was extracted by magnetic beads method. STR genotyping was determined using Identifiler kit.@*RESULTS@#The successful STR genotype rate of sperm cells isolated from mixture samples with LCM technique was 92.86% (13/14). The rate of differential lysis method was 7.14% (1/14). The successful rates between the two methods were statistically different (P < 0.05).@*CONCLUSION@#LCM technique can effectively exclude the interference of female cell component and isolate a small number of sperm cells to obtain a single male STR genotyping. LCM technique is obviously better than the differential lysis method.