Dating p

Since carbon contamination may also arise from organic molecules that have entered the bone or tooth matrix through soil detritus, microbial invasion or post-excavation handling, ABA-gelatinization is often followed by ultrafiltration through membranes that separate high molecular weight collagen chains from shorter peptides, amino acids and other small molecules.

DNA extraction, in contrast, is typically performed by lysis of the bone/tooth matrix using extraction buffers containing ethylenediaminetetraacetic acid (EDTA), a chelating agent that dissolves hydroxyapatite by means of sequestering calcium ions, and proteinase K, an enzyme that digests collagen and other proteins.

DNA was isolated from the EDTA, phosphate and lysis buffers by silica-based purification and converted into DNA libraries.

dating p-75

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.

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.

Over the past 70 years, radiocarbon dating has become an important tool for archaeology due to its precision in dating organic material up to approx. The wide-spread use of radiocarbon dating has been facilitated by the use of accelerator mass spectrometry (AMS), which determines the .

Carbon isotopes isolated from collagen are the primary source used in radiocarbon dating of bones and teeth, and current protocols require approximately 500 mg of bone or dentine with a minimum of 1% preserved collagen, providing insights into the history of human groups, their dispersals and interactions.

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, .

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.

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