Long-Term Tissue Preservation at Ambient Temperature for Post-Mass Fatality Incident DNA-Based Victim Identification.

Area of Science:

• Forensic Science
• Molecular Biology
• Biochemistry

Background:

• Effective tissue preservation is critical for DNA-based victim identification in mass fatality incidents (MFIs).
• Traditional methods like freezing may be impractical during prolonged power outages, such as in armed conflicts.
• Alternative, low-cost preservation methods are needed for long-term storage at ambient temperatures.

Purpose of the Study:

• To compare the long-term effectiveness of ambient temperature tissue preservation using salt and alcohol against chemical preservation and freezing.
• To evaluate DNA integrity and amplicon size for downstream Short Tandem Repeat-Polymerase Chain Reaction (STR-PCR) analysis.

Main Methods:

• Bovine muscle tissue was preserved using non-iodized salt, 40% alcoholic beverage, Allprotect™ Tissue Reagent, and freezing at -20 °C.
• Samples were analyzed at six time-points over a 24-month period.
• DNA integrity was assessed using gel electrophoresis, and STR-PCR amplicon size was determined.

Main Results:

• All four preservation methods maintained tissue viability and yielded STR-PCR amplicons > 200 bp over 24 months.
• Non-iodized salt showed superior preservation of DNA integrity, with high-molecular-weight DNA visible on gel electrophoresis.
• Other methods resulted in low-molecular-weight DNA smears, indicating greater degradation.

Conclusions:

• Non-iodized salt offers a simple, low-cost, and effective method for long-term tissue preservation at ambient temperatures for MFI victim identification.
• This method is particularly valuable in resource-limited settings or during emergencies with power instability.
• Further research could refine ambient temperature preservation protocols for forensic applications.