NCJ Number
121042
Journal
Chemical & Engineering News Volume: 67 Issue: 47 Dated: (November 1989) Pages: 18-27,30
Date Published
1989
Length
11 pages
Annotation
This article discusses DNA analysis techniques in relation to existing analytical procedures for examination of biological evidence. The significance of DNA profiling is the strong link it provides between a suspect and a particular piece of biological evidence.
Abstract
DNA analysis, similar to bloodtyping, is based on the existence of various genetic markers with individual characteristic profiles, the determination of frequency of each marker type, and the probability that an individual possesses a specific profile of markers. Forensic bloodstain analysis, in addition to DNA typing, can consist of ABO blood typing according to the Lattes method, absorption elution test, or enzyme-linked immunosorbent assay (ELISA), and polymorphic protein study by gel electrophoresis. DNA profiling is performed by two techniques, the restriction fragment length polymorphism (RFLP) analysis and the allele-specific oligonucleotide (ASO) DNA amplification or more commonly known as the polymerase chain reaction (PCR) analysis. Combination of the ASO technique with DNA amplification allows potential DNA profiling of a single human hair or a minuscule bloodstain. The RFLP offers greater sensitivity, but requires a larger sample, whereas PCR requires less sample, but is also less specific. The greatest concern with DNA profiling is false identification, although DNA experts claim harsh treatment of DNA only renders it unreadable. Standards for both analytical and interpretational aspects of DNA profiling are currently being developed.