DNA-Analysis Of Hair Simplified - Scientists Develop Process For Aggrieved Material
By Marietta Gross - Scoop Media Auckland
German legal scientists have discovered a DNA technique that will enable a reliable genetic fingerprint from "omitted hair" or hair that has fallen out of been removed from a body. Previously, police and forensic scientists were often unable to get a reliable match from omitted hair samples.
Medico-legal experts from the Johannes-Gutenberg-University rechtsmedizin.uni-mainz.de in Mainz have developed a new method for taking genetic fingerprints, which considerably simplifies the DNA-designation for single hairs and heavily aggrieved material. To date, it has been almost impossible to base an analysis on omitted hair, because of the absence of somatic cells within roots of omitted hair.
DNA contains all the genetic information of a human being and consists of four basic modules, the bases Adenine, Guanine, Thymine and Cytosine. It is found in the cell nucleus in the form of 46 chromosomes. Only five per cent of DNA contains coding regions, which means it is responsible for the actual forming and appearance of a person. The other 95 per cent are non-coding segments, which can differ in size and which do not carry information that is important for appearance. In this non-coding region there are sections, which vary between different persons and give a relatively unique criterion for recognition.
DNA-material can be easily
extracted from hair that is still growing. But omitted hair
normally does not contain any more somatic cells. Old or
aggrieved DNA is only existent in fragments. The scientists
from Mainz have simplified the aggrandisement of these
segments by means of polymerase chain reaction (PCR). The
experts tried to examine as many criteria of the heavily
aggrieved DNA as possible in one reaction. But only five to
seven criteria can be placed in such a multiplex. The new
method unifies two multiplexes for the PCR, which are later