A novel, 4-h DNA extraction method for STR typing of casework bone samples

Area of Science:

• Forensic Science
• Molecular Biology
• Genetics

Background:

• Bones from mass graves present challenges for DNA identification.
• Efficient DNA extraction is crucial for increasing success rates.
• Existing bone DNA extraction methods vary in efficiency and complexity.

Purpose of the Study:

• To develop and evaluate a quick and highly efficient DNA extraction method for human bones.
• To systematically compare the developed method against established protocols.
• To assess DNA yield, inhibitor removal, and STR profile quality for forensic casework.

Main Methods:

• A novel DNA extraction method was developed.
• The new method was compared with Hi-Flow silica-based, total demineralization (TD), and PrepFiler BTA methods.
• Seventy fresh and 22 casework bones were analyzed for DNA concentration and PCR inhibitor levels.

Main Results:

• The developed method yielded the highest median DNA concentrations for both fresh and casework bones.
• The developed method and PrepFiler BTA demonstrated superior removal of PCR inhibitors.
• 95.45% of casework STR profiles from the developed method met database entry standards, outperforming other methods.

Conclusions:

• The developed DNA extraction method is highly efficient for forensic casework involving bones.
• The method significantly reduces extraction time (to 4 hours) and is cost-effective.
• Optimizing both extraction method and bone sampling site (e.g., hand phalanges) enhances identification success.