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NCJRS Abstract

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NCJ Number: 229593 Find in a Library
Title: Validation of a Single Nucleotide Polymorphism (SNP) Typing Assay with 49 SNPs for Forensic Genetic Testing in a Laboratory Accredited According to the ISO 17025 Standard
Journal: Forensic Science International: Genetics  Volume:4  Issue:1  Dated:December 2009  Pages:34-42
Author(s): Claus Borsting; Eszter Rockenbauer; Niels Morling
Date Published: December 2009
Page Count: 9
Type: Report (Study/Research)
Format: Article
Language: English
Country: Ireland
Annotation: This study validated a multiplex assay with 49 autosomal single nucleotide polymorphisms (SNPs) developed for human identification for the purpose of forensic genetic testing in a laboratory accredited according to the ISO 17025 standard.
Abstract: A multiplex assay with 49 autosomal single nucleotide polymorphism (SNPs) developed for human identification was validated for forensic genetic casework and accredited according to the ISO 17025 standard. The multiplex assay was based on the SNPforID 52plex SNP assay [J.J. Sanchez, C. Phillips, C. Borsting, K. Balogh, M. Bogus, M. Fondevila, C.D. Harrison, E. Musgrave-Brown, A. Salas, D. Syndercombe-Court, P.M. Schneider, A. Carracedo, N. Morling, A multiplex assay with 52 single nucleotide polymorphisms for human identification, Electrophoresis 27 (2006) 1713-1724], where 52 fragments were amplified in 1 PCR reaction. The SNPs were analyzed by single base extension (SBE) and capillary electrophoresis. Twenty-three of the original SBE primers were altered to improve the overall robustness of the assay and to simplify the analysis of the SBE results. A total of 216 samples from 50 paternity cases and 33 twin cases were typed at least twice for the 49 SNPs. All electropherograms were analyzed independently by two expert analysts prior to approval. Based on these results, detailed guidelines for analysis of the SBE products were developed. With these guidelines, the peak height ratio of a heterozygous allele call or the signal to noise ratio of a homozygous allele call is compared with previously obtained ratios. A laboratory protocol for analysis of SBE products was developed where allele calls with unusual ratios were highlighted to facilitate the analysis of difficult allele calls. The guidelines for allele calling proved to be highly efficient for the detection of DNA mixtures and contaminated DNA preparations. DNA from two individuals was mixed in seven different ratios ranging from 1:1 to 1:10; all mixtures were easily identified as mixtures. Tables, figures, appendix, and references (Published Abstract)
Main Term(s): Forensic medicine
Index Term(s): Forensic sciences; Research methods; Scientific techniques; Testing and measurement
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