The exterior of the bone or tooth is usually mechanically removed (sanding) or treated with bleach and UV light to remove surface contaminants. 3. Extraction Methods
Over time, DNA strands break into very short fragments, typically between 30 and 100 base pairs. Ancient DNA: Methods and Protocols
The silica-based extraction method is the industry standard. DNA binds to silica in the presence of high concentrations of chaotic salts, allowing impurities to be washed away before the DNA is eluted into a clean buffer. 4. Library Preparation and Sequencing The exterior of the bone or tooth is
Once extracted, the DNA must be prepared for Next-Generation Sequencing (NGS). The silica-based extraction method is the industry standard
The goal of extraction is to release DNA from the mineral matrix (bone) while removing inhibitors like humic acids.
Synthetic DNA "adapters" are attached to the ends of the fragments, allowing them to bind to the sequencing platform.
A distribution of very short fragment lengths suggests the DNA is genuinely old rather than modern contamination. Conclusion