It is found within all living organisms and is occasionally preserved in ancient humans, animals, or plant remains. DNA is an exceptional source of information due to its structure which is compiled with a sequence of links and make up a DNA blueprint (Jones, Molecular Hunt). DNA is an excellent source for identifying individuals and showing genetic and evolutionary relationships. Ancient DNA (aDNA) specifically refers to DNA found within ancient remains, however, the extraction of DNA from these materials is extremely difficult. Ancient DNA is significantly modified due to the environmental impacts it is subjected to, such as oxidation processes which is a reason for the difficulty of finding unimpaired specimens for analysis (Kalmar, 2000). Furthermore, Ancient DNA is usually found in smaller quantities with the material that is found being fragmented and damaged by soil, UV rays or other DNA. The discovery of aDNA is only ever found in small amounts and in differing stages of decomposition. Previous studies have indicated that the best samples to use are that of tooth and bone as they are the more plentiful and better preserved than that of soft tissue remains (Kalmar, 2000). A handful of different methods of extraction of aDNA exist, including ethanol precipitation, the use of membranes for DNA concentration and silica binding …show more content…
Although there is no problem in detecting contamination derived from humans in animal remains, it can be more difficult to detect contemporary human DNA in ancient human remain samples (Paabo et.al, 1989). The measures to control contamination in the study of MTB in Iron Age human remains were focused on physical obstructions such as, surfaces and equipment. Equipment, including centrifuges, rotors, popettes and others, were cleansed prior to each experiment, DNA extraction was controlled to detect efficiency of the procedures. Water blanks were routinely changed with samples in PCR to scan for contamination. The strict controls used in this study allowed for some successful finds in the study of MTB. Five skeletons were studied with three showing evidence of infected wounds which is suggestive of Tuberculosis, whereas the other two skeletons displayed lesions that related to gastrointestinal infections, which may have been Tuberculosis. The origins of the skeletons were all dated back to the Iron Age and was regarded as a semi-nomadic rural economic society. This suggests that they undertook seasonal shifts with animals in a well-defined territory. The successful amplification and genotyping of the Mycobacterial DNA is indicative of how much potential the use of DNA and human remains has to further archaeological research, specifically in the understanding of Tuberculosis disease in Iron Age