A systematic approach to the sampling of dental DNA

As investigations into the forensic aspects of DNA analysis continue, the human tooth will play a dual role in identification. Dentin and enamel provide a protective enclosure for genomic and mitochondrial DNA as well as providing the basis for radiographic, biochemical, and ultrastructural forensic studies. The purpose of this investigation is to establish technical guidelines, based on histology and experimental evidence, for the management and sampling of dental DNA. The anatomic location of dental DNA is discussed with emphasis on the conservation of tooth structure during sampling. Ten pairs of maxillary right and left third molars were sampled for DNA following storage for 18 weeks at ambient temperature and humidity. Right third molars were crushed, whereas the left third molars were sectioned conservatively prior to sampling the DNA. The quantity and quality of human DNA obtained from each tooth was compared, as well as the radiographic appearance of remaining hard tissue and the overall simplicity of each approach. DNA typing was performed, both sequence and length based analyses, comparing teeth from the same individual and teeth from different donors. The results of this study suggest that the odontologist will maximize the dental DNA yield by crushing the entire specimen but that substantial yields of human DNA can be obtained by using a conservative technique that preserves the tooth structure. In addition, the method of sampling does not affect the ability to perform DNA typing analyses.