Factors affecting dental DNA in various real post-mortem conditions.

Area of Science:

• Forensic Science
• Molecular Biology
• Genetics

Background:

• Post-mortem DNA degradation poses significant challenges in forensic identification.
• Environmental factors and post-mortem interval (PMI) complicate DNA analysis.

Purpose of the Study:

• To evaluate the impact of ante-mortem and post-mortem factors on dental DNA quantity in forensic cases.
• To identify key variables affecting DNA yield from teeth for identification purposes.

Main Methods:

• Analysis of 95 teeth from 39 corpses under 6 different post-mortem conditions.
• DNA extraction from apical and cervical portions of tooth roots.
• Quantification of DNA concentration using real-time PCR (PowerQuant™ System/Promega).

Main Results:

• The post-mortem interval (PMI) was the most significant factor affecting dental DNA quantification (p < 0.001).
• Optimal DNA yields were observed within the first 10 days post-mortem, followed by a sharp decline.
• Burnt and fresh corpses yielded the most DNA, while skeletonized remains yielded the least.
• Dry, indoor conditions were superior to aquatic, outdoor, or buried environments for DNA preservation.

Conclusions:

• Post-mortem factors, particularly PMI and environmental conditions, substantially influence dental DNA yield.
• Ante-mortem factors like sex, age, and tooth type showed no significant effect on DNA yield.
• Understanding these factors is crucial for improving DNA-based forensic identification strategies.