Forensic study of sex determination using PCR on teeth samples

Area of Science:

• Forensic Science
• Molecular Biology
• Genetics

Background:

• Accurate sex determination is crucial in forensic investigations, especially when dealing with decomposed or fragmented human remains.
• Dental tissues offer a promising source of DNA for identification due to their resilience.

Purpose of the Study:

• To evaluate the efficacy of polymerase chain reaction (PCR) for sex determination using DNA extracted from various tooth components.
• To assess the reliability of this method under diverse challenging conditions, including long-term preservation, environmental exposure, and thermal degradation.

Main Methods:

• DNA extraction from dental pulp and hard tissues.
• Polymerase chain reaction (PCR) amplification targeting Y and X chromosome-specific alphoid repeat sequences.
• Testing DNA from teeth subjected to various preservation conditions (long-term storage, seawater, soil) and heat treatments.

Main Results:

• PCR demonstrated high sensitivity (0.5 pg genomic DNA) for detecting Y and X chromosome sequences.
• Successful sex determination was achieved from fresh teeth, teeth stored for 22 years, and teeth exposed to seawater and soil for varying durations.
• The method remained effective even after teeth were heated up to 200-250°C.
• In forensic cases, sex determination was successful from dental pulp of mummified remains and from hard dental tissues of skeletal remains submerged in water for extended periods.

Conclusions:

• PCR-based sex determination using tooth material is a robust and versatile forensic technique.
• The method is effective even with degraded DNA from teeth subjected to harsh environmental conditions and heat.
• This approach provides a valuable tool for sex determination in challenging forensic casework involving skeletal or mummified remains.