ABSTRACT
Prior to forensic implementation, a profiling system requires validation following the recommendations presented by the Technical Working Group on DNA Analysis Methods (TWGDAM). In this work two such systems, AmpFlSTR Profiler Plus and AmpFfSTR COfiler have been validated according to the guidelines provided by TWGDAM. Profiler Plus and COfiler simultaneously amplify nine and six STR loci respectively; both also amplify a portion of the amelogenin gene. Performance of the two STR multiplex systems under conditions set forth by TWGDAM was robust and reproducible, indicating that these systems are suitable for use in forensic analysis. Additionally, specific sections of the TWGDAM validation guidelines are especially valuable in terms of familiarizing users with particular limitations of the systems prior to taking on casework.
Subject(s)
Dental Enamel Proteins/genetics , Gene Amplification , Amelogenin , Electrophoresis, Capillary , Forensic Medicine/methods , Humans , Polymerase Chain Reaction , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
The application of resolution measurements to an electrophoretic system can give a quantitative analysis of the health of that system. Capillary electrophoresis has become a routine method for the analysis of DNA and resolution measurements can be used to assess the resulting electropherogram. A number of methods are available to evaluate resolution and three methods are detailed in the current work. Parameters such as polymer concentration and column length were also examined in terms of resolution, and changes therein, if these parameters were modified.
Subject(s)
DNA/analysis , Electrophoresis, Capillary/standards , Electrophoresis, Capillary/methods , Forensic Medicine/methods , Humans , Sensitivity and SpecificityABSTRACT
Capillary electrophoresis (CE) is a versatile technology with tremendous potential applications in forensic science. A refinement of the traditional slab-gel, separation occurs in a liquid polymer contained within a capillary. The capillary electrophoresis unit is computer-driven, semi-automating the loading and analysis of samples. As with any new technology, a full performance assessment is required before it may be implemented with confidence. This paper focuses on validation of CE technology for analysis of a portion of the X-Y homologous amelogenin gene used in gender determination. Typical Y/X ratios of peak heights for male samples were determined. Instrument linearity, sample resolution and reproducibility were examined. Samples subjected to contamination, extreme environmental conditions or extracted from a variety of substrates were also tested by CE. All samples typed correctly. Genetic material from a number of common non-primate animals was amplified with amelogenin primers. Some species yielded no product. Products derived from the animal samples that did amplify produced peaks on CE analysis readily distinguishable from those of human origin.
Subject(s)
Dental Enamel Proteins/genetics , Electrophoresis, Capillary/methods , Sex Determination Analysis , X Chromosome/genetics , Y Chromosome/genetics , Amelogenin , Animals , Blood Stains , DNA/analysis , DNA Fingerprinting/methods , Female , Gene Amplification , Humans , Male , Reproducibility of ResultsABSTRACT
Capillary electrophoresis is a relatively new technology for the forensic analysis of STRs, and may be an excellent alternative to traditional gel-based methods. Eighty samples, obtained from six different laboratories which had previously analyzed the samples using a variety of gel-based methods, were reanalyzed by CE. It was determined that CE could obtain the same allelic designation as that reported by the comparison laboratory. Seven different loci employing two separate multiplex amplifications were used for the comparison study. One basepair resolution and average standard deviations within the range of 0.075 to 0.117 basepairs were observed.
Subject(s)
DNA/analysis , Electrophoresis, Capillary/methods , Electrophoresis, Polyacrylamide Gel/methods , Forensic Medicine/methods , Repetitive Sequences, Nucleic Acid/genetics , Alleles , Base Composition , Clothing , DNA/blood , DNA/genetics , Genotype , Humans , PaperABSTRACT
The use and abuse of drugs in American society is recognized as a major issue among those who study youth. This paper addresses an often overlooked area of drug abuse: performance-enhancing drugs in sport. The reasons these vocational drugs are used by athletes are different from those of the recreational drug user. This paper examines the seriousness and prevalence of performance-enhancing drugs and presents the results of a series of interviews with steroid users to determine their attitudes. These attitudes and rationalizations suggest that an expanded view of drugs is required if performance-enhancing drug use is to be understood.
