ABSTRACT
In 1988, forensic DNA analysis was admitted for the first time in a US courtroom in a case of sexual assault. In 1985, Prof. Alec Jeffreys from Leicester University found that some regions in the human genome contain short DNA sequences that repeat next to each other at a given locus. DNA extraction consists in DNA purification from the other cell components and generally involves the following: cellular lysis in order to release DNA, protein removal and lipid removal and precipitation of DNA free from the other cellular components. The method is species-specific, highly sensitive, and allows quantification of a very small DNA quantity that is relevant when working with aged or degraded samples. Real-time polymerase chain reaction involves the use of an internal control to check for the presence of inhibitors and for any DNA template degradation in the sample. Short tandem repeats useful for forensic DNA analysis have been found in human sex chromosomes.
