For those in the area of either archaeogenetics or forensic genetics, are there any firm opinions on which human body parts function to preserve DNA best during decomposition, and would therefore be the the most suitable parts to process when extracting DNA for sequencing?
Does the answer change depending on whether the remains are somewhat recently buried (past few years) versus decades to hundreds to thousands of years old? Does the answer also depend on whether the body underwent preservation techniques, like embalming? I'm asking for situations where the body has not been frozen.
I have read that some specific types of teeth and bones may be ideal candidates, but any additional insight, experience, or nuance would be greatly appreciated.
Good afternoon!
If we talk about DNA extraction from ancient remains. Yes, indeed, teeth are very often used in this kind of research. However, this work requires high frequency and special laboratories, which are available in a very small number of institutes.
The time and conditions of burial are very important. So yes, mummification techniques are also very important. Embalming can significantly affect the preservation of DNA. The chemicals used for mummification or embalming can destroy or modify DNA, making it unusable for analysis.
Tooth is the best part due to it can with stand environmental changes and decomposition and it also has a high density for DNA Sequencing.
When extracting high-quality DNA from human remains for sequencing, the choice of body part depends on the condition and age of the remains. Here’s a breakdown of the most suitable body parts based on different scenarios:
1. Fresh or Recently Decomposed Remains:
• Blood: If available and not heavily degraded, it provides high-quality nuclear DNA.
• Soft Tissues (e.g., liver, muscle): Useful if decomposition is minimal.
2. Partially Decomposed Remains:
• Teeth: Especially the pulp cavity, as it protects DNA from environmental degradation.
• Compact Bone (e.g., femur, tibia): The dense cortical bone provides better protection against microbial contamination and environmental factors.
• Petrous Part of the Temporal Bone: The petrous bone is particularly valuable for ancient or highly degraded samples due to its exceptional DNA preservation.
3. Skeletal Remains (Advanced Decomposition):
• Teeth: Still a top choice for long-term DNA preservation.
• Petrous Bone: The best source for ancient DNA (aDNA) studies.
• Dense Long Bones (e.g., femur, tibia, humerus): Provide good-quality DNA from the compact bone.
• Phalanges (Finger/Toe Bones): Useful when larger bones are not available.
4. Cremated or Highly Degraded Remains:
• Teeth (Enamel-Protected Pulp): Often the only viable source.
• Compact Bone Fragments: In cases where the bone matrix is not entirely destroyed.
5. Special Cases (Ancient Remains):
• Petrous Bone: Almost always yields the best results for ancient DNA.
• Teeth: Especially valuable if the root or dentine is well-preserved.
Key Considerations:
• Environmental Factors: Humidity, temperature, soil pH, and microbial activity can impact DNA quality.
• Contamination Prevention: Use sterile tools and surfaces, and implement proper protocols to avoid modern DNA contamination.
- Badges
- Science topic