DNA in forensic studies?? - (Apr/06/2005 )
does the DNA dead bodies remain stable for very long periods to be
say for example if a person was dead for 1 year what well be the tissues
used to extract from ??????
DNA is relatively stable and able to be extracted from very old tissue (up to several thousand years), but it does depend on the conditions under which the tissue has been preserved. For example, if the body is frozen (e.g mammoth in ice) then the DNA can be relatively intact. However if the tissue is kept in a warm, wet environment, then the tissue (assuming that it has not been broken down by bacteria etc) is less likely to have intact DNA.
Under forensic conditions it would be best to attempt to get tissue that has not been exposed to the atmosphere such as in the interior of bones or deep muscle, if avaliable. Some tissues such as liver, kidney and brain contain massive amounts of nucleases, which will rapidly degrade any DNA they touch, thus these tissues are less likely to be able to be used for forensic purposes.
thanks alot for the useful information , i have another question, how
many years does the human hair last to be used in DNA extraction
processes (specially if the conditions of preservation are bad )?????????