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Development of a DNA-Based Multi-Species Identification and Quantification Assay

NCJ Number
Date Published
June 2014
59 pages
Based on the research reported here, the authors published four papers on species-specific DNA quantification of human, dog, cat, livestock, and poultry.
Species identification of forensic samples allows the analyst to determine the appropriate test when evaluating a wide range of biological evidence. Since most animal short tandem repeats (STR) analyses are species-specific, it is important to know the species of origin of the sample before attempting STR typing. The ability to accurately detect and quantify target DNA in mixed-species samples is crucial when target templates may be overwhelmed by non-target DNA. The use of accurate species-determining tests will enable analysts to optimize the typing tests used in a case and minimize the consumption of limited samples. This project combined the strengths of DNA-based taxon identification with that of a nuclear marker for DNA quantification into a simple and quick duplex single nucleotide polymorphism TaqMan assay. This robust and cost-efficient method for taxon differentiation and DNA quantification will be developed for test commercialization. The speciation and quantification assays have undergone scientific scrutiny, so as to ensure accuracy, precision, and reproducibility of the procedure; species-specificity, sensitivity, stability, and mixture analyses were part of its validation. Conditions for primers and probes were that these reagents identify sequences within target species that were conserved but contained sufficient polymorphisms such as SNPs that would enable the distinguishing of one target species from another. Target regions within these species' genomes were found for species-specific primers and probes. 8 figures, 4 tables, and 60 references

Date Published: June 1, 2014