DNA Fingerprinting: A substantial and imperative aid to forensic investigation

Abstract

Over the last three decades, the DNA profiling is based on a set of core short tandem repeat [STR] loci that are being widely used for forensic DNA testing, which provide sufficient discrimination power for most applications. Today’s forensic DNA tests employ PCR and capillary electrophoresis [CE] based fragment analysis methods to detect length variation in STRs. Presently most of the forensic laboratories are generating biparental autosomal STR based DNA profile on 16 to 20 and uniparental Y STR profile on 17 or 23 STR markers. A variety of commercial kits enable hassle free, fast and accurate multiplex amplification of these core STR loci. With the advanced 6 dye matrix supporting Genetic Analyser 3500/3500Xl, simultaneous amplification of much more STR markers is possible now, which is motivating kit provider companies to increase markers in a single multiplex for increased discrimination power. Besides the increase in number of markers in a single multiplex, the master mix in the preformulated kit is also improved for inhibitor tolerance as well as enabling fast PCR. In the last few years there has been growing interest in DNA phenotyping which is expected to enable investigation in solving blind cases by providing clues in cases where DNA typing fails. However, much more research is required to make this an established technology like DNA fingerprinting. The new arrival in forensic DNA typing is the launch of pre-formulated NGS based multiplex kits, providing option for simultaneous amplification of different types and more number of STR markers along with ancestry based SNPs in a single run, thus besides saving cost and time both, are more informative too. The article reviews diverse variants of DNA fingerprinting technology, its status and application in forensic case work.