Synthetic DNA "adapters" are attached to the ends of the fragments, allowing them to bind to the sequencing platform.
Success begins with choosing the right material. The (part of the skull) and tooth cementum are the "gold standards" because their high density protects DNA from environmental leaching.
Modern DNA from researchers or the environment is "fresher" and more intact than aDNA, making it easy for a tiny amount of modern DNA to overwhelm the ancient sample. 2. Sample Selection and Preparation Ancient DNA: Methods and Protocols
Software checks for high rates of C-to-T transitions at the ends of DNA fragments. If these "nicks" are present, it’s a signature of authenticity.
All work must be done in a dedicated "Clean Lab" with HEPA filtration, positive air pressure, and UV sterilization. Researchers wear full-body suits to prevent shedding their own DNA onto the samples. Synthetic DNA "adapters" are attached to the ends
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
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 Modern DNA from researchers or the environment is
A distribution of very short fragment lengths suggests the DNA is genuinely old rather than modern contamination. Conclusion
