Dr Karola Kirsanow from the Institute of Anthropolgy at Mainz explains how scientists research prehistory using DNA from ancient bones and teeth.
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00:00 [ Background Sounds ]
00:11 >> Hi, my name is Carla Kersnow, and I work at the Institute of Anthropology and Mines.
00:16 Here at the Institute, we research the prehistory of humans and domestic animals.
00:22 We use DNA from ancient bones and teeth to reconstruct prehistory.
00:27 This ancient DNA is very rare and very fragile, and it has to be analyzed
00:32 in dedicated facilities like the one you see here.
00:36 Let me guide you through it.
00:38 [ Music ]
00:44 I have some very old bones here that we plan to analyze.
00:47 The problem with old bones is that they contain very few ancient DNA molecules,
00:52 and they can become easily overwhelmed by modern DNA contaminants from the environment.
00:57 We follow a very particular procedure to make sure that the samples,
01:01 the rooms, and the people get cleaner with every step.
01:05 [ Music ]
01:31 This is the room where samples are photographed and documented.
01:34 [ Music ]
01:41 We try to select long bones or the roots of teeth for sampling.
01:45 [ Music ]
02:07 After the surface is removed, the bone is subsampled.
02:12 We then put the remaining sample in a UV light box.
02:16 [ Music ]
02:24 We mill and pulverize the bone or tooth sample to make the DNA inside more accessible.
02:31 [ Music ]
02:58 Now we're in the heart of the lab where the DNA is extracted from the sample.
03:03 Nobody is allowed to move around while somebody is working in here.
03:06 We try to avoid producing any turbulence.
03:11 We actually turn off the air circulation while the pipetting is being done.
03:15 [ Music ]
03:24 We extract the fumes after the work is done and the reaction tubes are closed.
03:29 [ Music ]
03:45 As I said before, DNA in bones is preserved in very small quantities.
03:50 Here we set up PCRs, a reaction to amplify the very few remaining molecules and create DNA libraries.
03:57 [ Music ]
04:06 This is the inner sanctum separated by two doors, very clean.
04:10 [ Music ]
04:22 Cleaning is the most important part of working in an ancient DNA laboratory.
04:26 We even have a waterproof UV bulb to irradiate our cleaning water.
04:30 [ Music ]
04:34 We have two rooms dedicated to cleaning our utensils like racks and bottles.
04:40 [ Music ]
05:00 The work goes on even after the researchers leave for the night
05:04 as computer programs continue to analyze the sequence data.
05:08 [ Music ]
05:14 We use highly parallel DNA sequencing methods to read the code of the ancient DNA.
05:20 After the DNA sequencing is complete, the computational work begins
05:24 and it lasts at least as long as the laboratory work.
05:28 Here we translate the ancient DNA code into information about the genetic relationships
05:33 between the prehistoric populations.
05:36 We want to know about the peoples of the past, who they were, where they came from,
05:41 where they migrated to, what diseases they had, and their relationships to the peoples of today.
05:47 [ Music ]
06:13 (upbeat music)