Comparing preservation substrates under field conditions for efficient DNA recovery in bone

Area of Science:

• Forensic Science
• Molecular Biology
• Bioarchaeology

Background:

• Bones are crucial for identifying human remains when other biological materials are unavailable.
• Maintaining DNA integrity in bone samples is vital for profiling, especially when refrigeration is not feasible.
• Standardized protocols for long-term bone sample storage under field conditions are lacking.

Purpose of the Study:

• To evaluate the impact of different storage conditions on DNA recovery from bone samples.
• To determine optimal buffer composition, temperature, and storage duration for DNA preservation in bones.
• To identify a suitable storage substrate for forensic bone samples in the absence of cooling.

Main Methods:

• Pig rib bones were used as a model system.
• Bones were stored in TENT, solid sodium chloride (NaCl), or ethanol-EDTA buffers.
• Storage conditions included 20°C and 35°C for 10, 20, and 30 days.
• DNA was extracted after drying and grinding bones, followed by quantification.

Main Results:

• Storage temperature and time did not significantly affect DNA yield.
• DNA recovery was significantly higher from bones stored in solid NaCl or ethanol-EDTA compared to TENT.
• Solid NaCl facilitated bone dehydration and grinding more effectively than TENT.
• Solid NaCl proved superior to ethanol-EDTA due to its non-toxic, non-hazardous, and leak-proof properties.

Conclusions:

• Solid sodium chloride (NaCl) is a highly effective and practical substrate for storing bone samples for DNA analysis when refrigeration is unavailable.
• The findings support the use of NaCl as a recommended storage medium for forensic bone samples under field conditions.
• This method enhances DNA preservation and simplifies sample processing, crucial for identification purposes.