Chapter 28 Forensic DNA typing technologies: a review

Abstract

Publisher Summary This chapter discusses forensic deoxyribonucleic acid (DNA) typing technologies. DNA typing has advantages over traditional protein assays, first of all because it is more informative and can be analyzed in minute or degraded material as DNA is physically much more resistant to degradation than proteins. In addition, the same DNA genotype can be obtained from any tissue (i.e., blood, saliva, semen, hair, skin, or bones), whereas the analysis of protein markers is restricted to cells where these proteins are expressed. DNA analysis has become a standard method in forensic genetics as it is currently used by most of the labs for the majority of forensic genetic expertise and especially in criminal forensic casework (stain analysis and hairs) and identification. Technologies used for DNA typing for forensic purposes differ in their ability to differentiate two individuals and in the speed and sensitivity with which results can be obtained. The speed of analysis has dramatically improved for forensic DNA analysis. DNA testing that previously took more than one week can now be performed in a few hours. Southern blotting with single-locus probe (SLP) has been used for paternity testing and forensic stain typing but is rarely used nowadays except in complicated paternity cases.