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 en amel provide a protective enclosure for genomic and mitochondrial DNA as well as providing the basis for radiographic, biochemical, and ultr astructural forensic studies. The purpose of this investigation is to establish technical guidelines, based on histology and experimental ev idence, for the management and sampling of dental DNA. The anatomic lo cation of dental DNA is discussed with emphasis on the conservation of tooth structure during sampling. Ten pairs of maxillary right and lef t third molars were sampled for DNA following storage for 18 weeks at ambient temperature and humidity. Right third molars were crushed, whe reas the left third molars were sectioned conservatively prior to samp ling the DNA. The quantity and quality of human DNA obtained from each tooth was compared, as well as the radiographic appearance of remaini ng hard tissue and the overall simplicity of each approach. DNA typing was performed, both sequence and length based analyses. comparing tee th from the same individual and teeth from different donors. The resul ts of this study suggest that the odontologist will maximize the denta l DNA yield by crushing the entire specimen but that substantial yield s of human DNA can be obtained by using a conservative technique that preserves the tooth structure. In addition, the method of sampling doe s not affect the ability to perform DNA typing analyses.