U.S. flag

An official website of the United States government, Department of Justice.

Inter-Sample Contamination Detection Using Mixture Deconvolution Comparison

NCJ Number
Forensic Science International-Genetics Volume: 40 Dated: May 2019 Pages: 160-167
Date Published
May 2019
8 pages
This study used a mixture-to-mixture comparison tool to examine the prevalence of sample-to-sample contamination that could occur from two laboratory mechanisms, one during DNA extraction and one during electrophoresis.

A recent publication reported the ability to compare two mixed DNA profiles and consider their probability of occurrence if they do or do not have a common contributor. This ability has applications to both quality assurance (to test for sample to sample contamination) and for intelligence gathering purposes (whether the same unknown offender donated DNA to multiple samples). The current study identified any potential common DNA donors and investigated these for their risk of contamination from the two proposed mechanisms. Although it did not identify any contamination, the study inadvertently found a potential intelligence link between samples, showing the use of a mixture-to-mixture comparison tool for investigative purposes. (publisher abstract modified)

Date Published: May 1, 2019