Forensic application of DNA ‘fingerprints’

Abstract

Many highly polymorphic minisatellite loci can be detected simultaneously in the human genome by hybridization to probes consisting of tandem repeats of the 'core' sequence. The resulting DNA fingerprints produced by Southern blot hybridization are comprised of multiple hypervariable DNA fragments, show somatic and germline stability and are completely specific to an individual. We now show that this technique can be used for forensic purposes; DNA of high relative molecular mass (Mr) can be isolated from 4-yr-old bloodstains and semen stains made on cotton cloth and digested to produce DNA fingerprints suitable for individual identification. Further, sperm nuclei can be separated from vaginal cellular debris, obtained from semen-contaminated vaginal swabs, enabling positive identification of the male donor/suspect. It is envisaged that DNA fingerprinting will revolutionize forensic biology particularly with regard to the identification of rape suspects.

A Novel On‐Chip Method for Differential Extraction of Sperm in Forensic Cases

“…Even while performing lengthy sample process steps, a significant amount (60–90%) of male DNA may be lost during existing procedures as reported in the literature 10, 11, 12, 13. Here, we present a next‐generation differential extraction technology that is, to the best of our knowledge, the most rapid, reliable, accurate, user‐friendly method available.…”

“…This process involves time‐consuming, labor‐intensive steps of selective cell lysis, centrifugation, and separation into female and male cell fractions (i.e., differential extraction) which can take up to 8 h, contributing significantly to the backlog problem. However, it has been reported that this cell separation process results in losses of 60–90% of the male DNA 10, 11, 12, 13. Although there have been multiple attempts for alternative methods to differentially extract sperm using acoustic trapping,14 antibody‐based capture,15 laser microdissection,16, 17, 18 nuclease‐based approaches,19 and magnetic bead‐based separation,20, 21 these methods have not been broadly available in practical applications due to the complexity and low separation yield for sperm.…”

Investigation of paternity establishing without the putative father using hypervariable DNA probes

“…Hypervariable DNA polymorphisms has been widely applied, in individual identification (Jeffreys et al, 1985b;Gill et al, 1985;Giusti et al, 1986), and in paternity suits (Jeffreys et aI., 1985a;Baird et al, 1986;Allen et al, 1989). Most of them are multi-locus probes that recognize several loci under the conditions of reduced stringency.…”

DNA profiling: The first 30years

“…This year marks 30 years since the seminal publications by Alec Jeffreys et al appeared in Nature (1)(2)(3). At the time Jeffreys was studying gene structure and function; when he found regions of DNA that were highly variable he had the insight to recognize that hypervariable regions could be applied to human identification.…”