Impact of Chemical Exposure on the Quality of DNA Extracted from Teeth: A Potential Application for Forensic Study in Burkina Faso

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Résumé

Introduction: Forensic investigations involving the discovery of a corpse or human remains aim to identify the individual involved. Sometimes, the body is subjected to chemical solutions with the intention of disintegrating or completely altering it. This further complicates identification. Nevertheless, it is possible to recover sufficient DNA from dental tissues. The present study aims to determine the effects of chemical solutions on the physical structure of teeth and also on their DNA. Methods: Teeth from Sus scrofa pigs were subjected to acidic (NHO3, H2SO4, and HCl) and basic (NaOH) solutions for specific durations (up to 144 h). Observations were recorded at regular intervals to document the effects on the tissues. After sampling, DNA was extracted using the PrepFiler® BTA Forensic DNA extraction kit. The extracted DNA was quantified using a BioDrop spectrometer and then amplified by conventional PCR using ACTB and mtDNA primers. The resulting amplicons were subjected to 2% agarose gel electrophoresis. After migration, the fragments were visualized under UV light in a trans-illuminator. Results: The teeth were completely dissolved in HCl and HNO3 solutions after 8 hours of immersion. The other solutions had no significant impact on the physical integrity of the teeth. A total of 32 teeth samples were obtained after exposure to the chemical solutions. The DNA obtained was of sufficient quantity and acceptable purity for the majority of samples. Conclusion: This study has shown that chemical solutions affect biological tissues and their DNA. Amplification of nuclear and mitochondrial DNA sequences by conventional PCR confirms that teeth remain the best source of DNA due to their resistance to degradation factors.

Mots-clés

Tooth, DNA, ACTB, mtDNA, PCR