If the sample has low endogenous DNA (e.g., 99% of the DNA is from soil bacteria), researchers use "baits"—RNA probes that match the target genome—to "fish out" the human or animal DNA of interest. 5. Bioinformatic Authentication The final step is proving the DNA is actually ancient.
A distribution of very short fragment lengths suggests the DNA is genuinely old rather than modern contamination. Conclusion Ancient DNA: Methods and Protocols
The goal of extraction is to release DNA from the mineral matrix (bone) while removing inhibitors like humic acids. If the sample has low endogenous DNA (e