[Influence exerted by environmental and physicochemical factors on the results of sex identification of human dental pulp by polymerase chain reaction].

Sex identification of human tooth is an important aspect of individual identification in forensic science practice. This study was designed to determine the effects of environmental and physicochemical factors (EPF) on the deoxyribonucleic acid (DNA) from dental pulp and PCR result. Extracted teeth were subjected to the following treatment varying pH (2, 7, 10) solution; 10% formalin, 75% ethanol; different temperature (-20 degrees C, 4 degrees C, 25 degrees C, 37 degrees C, boiling, burning); humidity (20%, 66%, water submergence); burying the teeth outdoors; and aging (teeth stored at room temperature for 1.5, 3.5 and 8 years). DNA was extracted from the tooth followed by agarose gel electrophoresis for the purpose of DNA assay and quantity determination. Amplification was carried out using a pairs of primer Y1.1 and Y1.2. The results of the study showed that, 154 bp fragment was obtained in all male teeth, whereas no 154 bp fragment was found in a female fresh tooth. 154 bp fragment bands were not observed in case of teeth subjected to burial outdoors for 10 weeks, submergence in water for 10 weeks, soak in pH 2 solution for 10 weeks, and combustion for 10 minutes; only faint bands were observed in case of teeth subjected to 66% humidity and pH 10 solution for 10 weeks and combustion for 5 minutes; obvious bands were observed in the rest cases. In addition, the quality of DNA from dental pulp affected PCR amplification result. The integrity of DNA isolated was categorized as being high-molecular-weight (HMW), HMW with partial degraded DNA, completely degraded DNA, completely degraded and not detected.(ABSTRACT TRUNCATED AT 250 WORDS)