Thus, there was a desire to design and refine the graphitization system.
We therefore tested as a third reagent the acidic monosodium buffer (subsequently referred to as ‘acidic phosphate’), which combines the release of DNA with mild demineralization of the bone matrix.
For each of these reagents we evaluated the efficiency of DNA retrieval while monitoring possible losses of collagen and the accuracy of the resultant radiocarbon dates.
Since carbonates in the mineral fraction of hard tissues are exchanged with those present in the environment, in which a first treatment with hydrochloric acid solubilizes carbonates and hydroxyapatite, the main inorganic component of bones and teeth, a second treatment with sodium hydroxide removes other organic molecules such as humic acids, and a third treatment with hydrochloric acid removes atmospheric carbon dioxide absorbed during the base treatment.
The resulting collagen is then incubated in acid at high temperature to produce soluble gelatine.
We also detect no skews in radiocarbon dates compared to untreated samples.
Given the different material demands for radiocarbon dating (500 mg of bone/dentine) and DNA analysis (10–100 mg), combined DNA and collagen extraction not only streamlines the sampling process but also drastically increases the amount of DNA that can be recovered from limited sample material.Current protocols for ancient DNA and radiocarbon analysis of ancient bones and teeth call for multiple destructive samplings of a given specimen, thereby increasing the extent of undesirable damage to precious archaeological material.Here we present a method that makes it possible to obtain both ancient DNA sequences and radiocarbon dates from the same sample material.Therefore, the biomolecules required for radiocarbon dating and ancient DNA analysis are presumably located in different fractions of the bone matrix, suggesting that it might be feasible to retrieve both from a single sample by targeting the inorganic and organic components of the bone/tooth matrix separately.Such a combined method for DNA and collagen extraction would not only reduce the number of samplings and thereby the amount of material required to perform both techniques, but also substantially increase the amount of material available for genetic analyses.The first is EDTA, the reagent regularly used in ancient DNA extraction.