RESUMO
OBJECTIVE: To observe the length heteroplasmy and point heteroplasmy in human mtDNA control region. METHODS: The peripheral blood, buccal cell, and single hair shaft from 50 individuals and 16 family members, related in their maternallineage were analyzed by direct sequencing, and clones from 20 individuals whose mtDNA sequences have a T-C transition at 16189 nt were sequenced. RESULTS: No point heteroplasmy were observed in peripheral blood, buccal cell, single hair shaft from the same individual, neither in maternally related individuals. Length heteroplasmy was observed in those individuals with a homopolymeric tract and the different clones from the same individual has different proportions of length variants, but the hair shafts from the same individual were very similar to the measurements made from blood DNA. No length heteroplasmy was observed between different tissues from the same individual. CONCLUSION: mtDNA sequences have a characteristic of high consistency and genetic stability, mtDNA sequencing is a suitable tool for forensic applications such as individual identification.
Assuntos
Análise Mutacional de DNA/métodos , DNA Mitocondrial/genética , Heterogeneidade Genética , Mutação Puntual , Sequência de Bases , DNA Mitocondrial/análise , Células Epiteliais , Cabelo/química , Humanos , Boca/citologia , Polimorfismo Genético/genéticaRESUMO
AIM: To establish a new chemiluminescent assay with high sensitivity for detecting E. coli O157:H7 in food. METHODS: The assay was established based on the alkaline phosphatase (ALP) labeled anti-E. coli O157:H7 antibody, which reacted with an excellent chemiluminescent reagent, 3(2' spiroadamantane)4 methoxy 4(3''phosphoryloxy) phenyl 1,2 dioxetane (AMPPD) buffer solution and emitted the photons. RESULTS: The sensitivity of chemiluminescence assay was 850, and the linear range was 1000-50,000. The intra- and interassay CV values (CVs) were respectively below 15% and 20%. The correlation coefficient was 0.9807 by comparing with the conventional counting method. CONCLUSION: The chemiluminescent immunoassay is more accurate than other methods in the detection of concentration of E. coli O157:H7 in samples.