title: NIST mixed stain studies #1 and #2: interlaboratory comparison of DNA quantification practice and short tandem repeat multiplex performance with multiple-source samples.
abstract: The Mixed Stain Study 1 (MSS1, Apr.-Nov. 1997) and Mixed Stain Study 2 (MSS2, Jan.-May 1999) evaluated multiplexed short-tandem repeat (STR) DNA typing systems with samples containing DNA from more than one source. These interlaboratory challenge studies evaluated forensic STR measurement, interpretation, and reporting practice using well-characterized samples of very different analytical difficulty. None of the relatively few errors reported in either exercise resulted in a false identification of a reference source; several errors in evaluating the unknown source in three-source samples would hinder matching the profile in any archival database. None of the measurement anomalies reported is associated with any particular STR multiplex; all DNA amplification anomalies are associated with inefficient DNA extraction, inaccurate DNA quantitation, and/or analytical threshold policies.
authors.affiliation: Analytical Chemistry Division, Chemical Science and Technology Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Duewer
authors.forename: M C
authors.initials: MC
authors.lastname: Kline
authors.forename: J W
authors.initials: JW
authors.lastname: Redman
authors.forename: P J
authors.initials: PJ
authors.lastname: Newall
authors.forename: D J
authors.initials: DJ
authors.lastname: Reeder
mesh_terms: D001769:Blood; D016172:DNA Fingerprinting; D016208:Databases, Factual; D005554:Forensic Medicine / Q000379:methods; D006801:Humans; D015588:Observer Variation; D016133:Polymerase Chain Reaction; D015203:Reproducibility of Results; D012661:Semen; D013048:Specimen Handling; D020080:Tandem Repeat Sequences / Q000235:genetics*