Skip to comments.When the Gloves Come Off – Why We Do Not Use Gloves to Handle Artifacts in the Field
Posted on 11/09/2017 11:05:54 PM PST by SunkenCiv
What about DNA? We have gotten a number of comments from people, who are concerned about DNA-contamination. Are we contaminating preserved ancient DNA material on the surface of the artefacts by touching the objects with our bare hands?
It is important to have a realistic picture of the preservation conditions at the ice. The vast majority of the objects have been repeatedly exposed to the elements, even though they still look incredibly well preserved, compared to normal artifacts. The inside structure of the artifacts is in fact remarkably intact, but the surfaces are weathered to a varying degree. This would have removed the DNA from the people who originally handled them thousands of years ago.
Even if the ancient DNA should still be preserved in rare cases, the problem of contaminating samples with modern DNA is not really a problem anymore. In the early days of DNA research, there were reports of finding preserved DNA on ancient human bone. These later turned out to be modern contamination. Modern DNA techniques, however, have no problems separating original ancient DNA from modern contamination (read the seminal paper on this issue here). Ancient DNA has now been extracted from human bones which have been stored for in the museum vaults for decades and handled by a number of museum staff. Today, modern contamination is really just an issue, if the amount of contamination is very high compared to the sample size. This is why researchers are very careful when handling tiny DNA samples in the laboratory.
(Excerpt) Read more at secretsoftheice.com ...
Viking Age and Medieval horse dung found in the glaciated mountain pass at Lendbreen, together with horse bones and horseshoes. Photo: Secrets of the Ice.
I wonder how often even considering working with possible DNA evidence in archeological finds even comes up? I’m guessing it’s not that often.
It’s still relatively new.
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