Define ams dating
To determine whether it is feasible in principle to extract DNA and collagen from the same sample material without affecting radiocarbon dates, we used a dentistry drill to remove 7 g of powder from a 300-year-old horse bone (sample A) close in age to the upper limit of radiocarbon dating, and 8 g of powder from a C isotopes (see Table 1 and Supplementary Table S1 for details on the samples used in this study).The powder from each sample was split into 500 mg aliquots, which were then either subjected directly to collagen extraction and dating, or incubated with EDTA, neutral, or acidic phosphate buffers to release DNA (see Fig.In contrast to AMS radiocarbon dating, genetic analysis of ancient bones and teeth is often feasible even from small amounts of sample material.
This is achieved by releasing DNA from the bone matrix through incubation with either EDTA or phosphate buffer prior to complete demineralization and collagen extraction utilizing the acid-base-acid-gelatinization and ultrafiltration procedure established in most radiocarbon dating laboratories.
Using a set of 12 bones of different ages and preservation conditions we demonstrate that on average 89% of the DNA can be released from sample powder with minimal, or 38% without any, detectable collagen loss.
1a for a schematic overview of the experimental design).
Following DNA release, half of the aliquots were used for collagen extraction and dating, and half were incubated with an EDTA/proteinase K buffer commonly used in ancient DNA extraction to achieve full lysis of the bone powder and release any residual DNA.
Here we explored the feasibility of releasing DNA from ancient bones prior to collagen extraction using an ABA-gelatinization procedure followed by ultrafiltration.
More specifically, we tested three reagents that might enable the recovery of DNA without degrading the organic component of the bone/tooth matrix.
Schematic overview of the experiments performed in this study.
(a) In an initial experiment, two bone samples were used to evaluate the suitability of EDTA as well as neutral and acidic phosphate buffers for releasing DNA prior to radiocarbon dating.
The first is EDTA, the reagent regularly used in ancient DNA extraction.
EDTA is carbon-rich and synthesized from sources that contain only stable carbon isotopes (“old” carbon, .
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.