title: Investigation into stutter ratio variability between different laboratories.
abstract: The determination of parameters such as stutter ratio is important to inform a laboratory's forensic DNA profile interpretation strategy. As part of a large data analysis project to implement a continuous model of DNA profile interpretation we analysed stutter ratio data from eight different forensic laboratories for the Promega PowerPlex(®) 21 multiplex. This allowed a comparison of inter laboratory variation. The maximum difference for any one laboratory from the average of the best fit determined by the model was 0.31%. These results indicate that stutter ratios calculated from samples analysed using the same profiling kit are not expected to differ between laboratories, even those using different capillary electrophoresis platforms. A common set of laboratory parameters are able to be generated and used for profile interpretation at all laboratories using the same multiplex and cycle number, potentially reducing the need for individual laboratories to determine stutter ratios.
authors.affiliation: ESR, Private Bag 92021, Auckland 1025, New Zealand; Department of Statistics, University of Auckland, Private Bag 92019, Auckland 1025, New Zealand. Electronic address: Jo.bright@esr.cri.nz.
authors.forename: Jo-Anne
authors.initials: JA
authors.lastname: Bright
authors.affiliation: Department of Statistics, University of Auckland, Private Bag 92019, Auckland 1025, New Zealand.
authors.forename: James M
authors.initials: JM
authors.lastname: Curran
mesh_terms: D016477:Artifacts; D016172:DNA Fingerprinting; D053803:Forensic Genetics; D006801:Humans; D007753:Laboratories / Q000706:statistics & numerical data*; D008957:Models, Genetic; D060885:Multiplex Polymerase Chain Reaction; D012044:Regression Analysis
keywords: DNA interpretation; Forensic DNA; PowerPlex(®) 21; Stutter