Evaluation of macroscopic changes and the efficiency of DNA profiling from burnt teeth.

Identification of human remains subjected to incineration is extremely challenging. Our study evaluates the macroscopic changes and efficiency of DNA profiling in burnt teeth under controlled temperature and time conditions. 28 teeth were exposed to temperatures between 100 and 700°C for a duration of 1-15min. Two non-burnt teeth were used as control. Macroscopic changes were evaluated and recorded. DNA was extracted using a silica-based methodology. Efficiency of DNA profiling was assessed through Quantitative PCR for STRs. Burnt teeth reached chalky white appearance at 400°C 5min and fractures were observed from 300°C 10min. Amplification of STRs was very low from 300°C and 1 or 5min. In contrast, the housekeeping gene, GAPDH, was amplified in all combinations of temperatures and times. Although it is possible to amplify the housekeeping gene at high temperature, DNA profiling is difficult to obtain, probably due to small size of these regions making them more prone to degradation.