ABSTRACT
The reliability of a D1S80 typing procedure has been evaluated using simulated forensic specimens. D1S80 alleles were detectable in DNA recovered from bloodstains exposed to sunlight for up to 20 weeks. However, D1S80 alleles were undetectable in semen stains after six weeks sunlight exposure. Analysis of blood and semen that had been deposited on a variety of substrates and examined over a twenty-week period, revealed no systematic influence of substrate on the ability to type D1S80. A study in which body fluids were exposed to household chemical substances, such as bleach, acids, oil, and gasoline, indicated that only HCl and bleach had a deleterious effect on the ability to type D1S80. In addition, personal care chemical products were without effect on D1S80 allele patterns derived from semen. Exposure of blood and semen to four different species of microorganisms resulted in no alteration of D1S80 genotype patterns in these body fluids. D1S80 genotypes could be reliably determined even when body fluids from different individuals were mixed. DNA from no animals other than humans and higher primates could be amplified at locus D1S80 when the DNA had been isolated through an organic procedure. These studies, in concert with the reports of others, indicate that the procedures for the amplification and detection of genetic variation at locus D1S80 are suitable for use on forensic evidentiary materials.
Subject(s)
Alleles , DNA/analysis , DNA/blood , Saliva/chemistry , Semen/chemistry , Animals , Bacteria , Female , Forensic Medicine , Humans , Male , Polymerase Chain Reaction , Soil , Sunlight , Vaginal SmearsABSTRACT
Allele frequencies for the locus D1S80 were determined in African American, Caucasian, Southeastern Hispanic, Southwestern Hispanic, and Oriental sample populations using the polymerase chain reaction and subsequent electrophoresis and silver staining of the amplified products. Due to the presence of anodal and cathodal electrophoretic variants (in reference to the steps in an allelic ladder), allele frequencies were established using a classification protocol based on the steps in the allelic ladder. All sample populations met Hardy-Weinberg expectations for D1S80. In addition, there was no evidence for association of alleles between the loci D1S80 and D1S7. The product of allele frequencies from the data from the sample populations in this study can be used in forensic analyses and paternity tests to estimate the frequency of a D1S80 DNA genotype.
Subject(s)
Asian/genetics , Black People/genetics , DNA/genetics , Forensic Medicine , Genetic Markers/genetics , Hispanic or Latino/genetics , Minisatellite Repeats , White People/genetics , Alleles , Blood Stains , Chromosome Mapping , Electrophoresis, Polyacrylamide Gel , Gene Frequency , Humans , Polymorphism, Restriction Fragment LengthABSTRACT
The interlaboratory typing of DNA specimens that have been amplified at the D1S80 locus necessitates the use of a standard allelic reference ladder. This communication describes a technique in which individual, amplified alleles are isolated, combined, and amplified by PCR to produce a functional reference ladder composed of many of the alleles that occur at this locus. The amplified ladder can serve directly as a template source for production of the next generation of reference ladder. This process, in which each amplified ladder serves as the template for the next has been carried through multiple generations.
