Quantitative and qualitative analysis of DNA extracted from postmortem muscle tissues

Area of Science:

• Forensic Science
• Molecular Biology
• Genetics

Background:

• Postmortem DNA degradation poses challenges for forensic identification.
• Muscle tissue is a potential source for DNA extraction in forensic investigations.

Purpose of the Study:

• To evaluate the suitability of postmortem muscle DNA for Restriction Fragment Length Polymorphism (RFLP) analysis.
• To determine the impact of storage conditions on DNA quality and RFLP pattern integrity.

Main Methods:

• DNA extraction from 33 postmortem muscle specimens.
• Analysis using hypervariable minisatellite probes (MZ 1.3) and locus-specific probes (g3, MS1, MS43).
• Assessment of DNA degradation and RFLP pattern quality under different storage conditions (cold storage, room temperature).

Main Results:

• Despite partial DNA degradation after cold storage, over 90% of samples up to 3 days postmortem yielded good RFLP patterns.
• Room temperature storage significantly increased DNA degradation, with only 30% showing good RFLP patterns after 8 days.
• DNA quality for RFLP did not correlate with total or high-molecular-weight DNA quantities.
• DNA fingerprinting successfully ascertained a familial relationship.

Conclusions:

• Postmortem muscle tissue yields sufficient high-quality DNA for RFLP analysis for individual identification.
• Optimal storage conditions are crucial to maintain DNA integrity for reliable forensic results.
• RFLP analysis of muscle DNA is a highly useful tool in forensic autopsies.