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NIST Interlaboratory Studies Involving DNA Mixtures (MIX05 and MIX13): Variation Observed and Lessons Learned



John Butler, Margaret C. Kline, Michael D. Coble


Interlaboratory studies are a type of collaborative exercise in which many laboratories are presented with the same set of data to interpret, and the results they produce are examined to get a "big picture" view of the effectiveness and accuracy of analytical protocols used across participating laboratories. In 2005 and again in 2013, the Applied Genetics Group of the National Institute of Standards and Technology (NIST) conducted interlaboratory studies involving DNA mixture interpretation. In the 2005 NIST MIX05 study, 69 laboratories interpreted data in the form of electropherograms of two-person DNA mixtures representing four different mock sexual assault cases with different contributor ratios. In the 2013 NIST MIX13 study,108 laboratories interpreted electropherogram data for five different case scenarios involving two, three, or four contributors, some of them potentially related. This paper describes the design of these studies, the variations observed among laboratory results, and lessons learned.
Forensic Science International: Genetics


forensic DNA, DNA mixture, mixture interpretation, interlaboratory study, collaborative exercise, MIX05, MIX13, forensic science


Butler, J. , Kline, M. and Coble, M. (2018), NIST Interlaboratory Studies Involving DNA Mixtures (MIX05 and MIX13): Variation Observed and Lessons Learned, Forensic Science International: Genetics, [online], (Accessed April 15, 2024)
Created August 1, 2018, Updated March 26, 2024