RESUMEN

The aim of this study was to evaluate the extraction of dental DNA exposed to different chemical solutions. The sample was composed by 15 subjects, from which 5 samples of oral mucosal cells (reference population) and 15 teeth (experimental population) were collected. The experimental population was divided in three equal parts, which were exposed to different chemical solutions, namely hydrochloric acid (HCl) at 37 %, formaldehyde (CH2O) at 10 % and sodium hypochlorite (NaOCl) at 2.5 %. The DNA from the oral mucosa was extracted using organic method, while the dental DNA was extracted using the AFDIL method, including amplification by PCR and sequencing through capillary electrophoresis. The DNA exposed to hydrochloric acid dissolved, lacking extraction. The exposure of teeth to formaldehyde and sodium hypochlorite did not interfere in the extraction of DNA, once the amplification was visible in both experimental populations. The present outcomes demonstrated that DNA extraction may be limited under exposure to chemical solutions.

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El objetivo de este estudio fue evaluar la extracción de ADN dental expuesto a diferentes soluciones químicas. La muestra estuvo compuesta por 15 sujetos, de los cuales se recogieron 5 muestras de células de la mucosa oral (población de referencia) y 15 dientes (población experimental). La población experimental se dividió en tres partes iguales, que fueron expuestas a diferentes soluciones químicas, a saber, ácido clorhídrico (HCl) al 37 %, formaldehído (CH2O) al 10 % e hipoclorito de sodio (NaOCl) al 2,5 %. El ADN de la mucosa oral se extrajo utilizando el método orgánico, mientras que el ADN dental se extrajo utilizando el método AFDIL, incluyendo la amplificación por PCR y la secuenciación a través de electroforesis capilar. El ADN expuesto al ácido clorhídrico se disolvió, careciendo de extracción. La exposición de los dientes al formaldehído e hipoclorito de sodio no interfirió en la extracción de ADN, una vez que la amplificación era visible en ambas poblaciones experimentales. Los resultados actuales demostraron que la extracción de ADN puede ser limitada bajo la exposición a soluciones químicas.

Asunto(s)

Humanos , Dermatoglifia del ADN/métodos , Odontología Forense/métodos , Soluciones , Diente , ADN/análisis , Genética Forense

RESUMEN

In a joint Brazilian-German case study, distribution patterns of microorganisms were compared with environmental variables in the tropical coastal Manguaba lagoon in northeast Brazil, which is situated downstream of several sugar cane processing plants . 16S rDNA and 16S rRNA single strand conformation polymorphism (SSCP) gene fingerprinting were used to follow the composition and distribution of microorganisms throughout the salinity gradient of the lagoon. Potentially abundant microorganisms were identified by sequencing representative SSCP bands. It could be demonstrated that the distribution of microbes was in close relation to the physico-chemical environmental settings and followed a common scheme. In the in- and outlet areas of the lagoon rather transient microbial communities were found, whereas in the central part a stable, diverse community was encountered, that due to the long residence time of the water, had ample time for development and adaptation.