Development and Testing of a Rapid Multiplex Assay for the Identification of Biological Stains

The Principal Investigator, Kevin M. Legg, will develop and rigorously test a faster, more accurate, and more sensitive multiplex assay for the simultaneous identification of saliva, semen, and vaginal secretions. This assay will be developed using a triple quadruple mass spectrometer (QQQ) utilizing the multiple reaction monitoring (MRM) technique. This technique uses a two-fold ion-filtration method where target peptides and their subsequent fragmentation ions are accurately detected even against the complex background of non-target molecules present in any body fluid. The researcher will evaluate and select optimal ions for use in high-specificity MRM biomarker assays from human saliva, semen and vaginal secretions. He will develop and optimize a multiplex QQQ_MRM mass-spectrometry assay for saliva, semen and vaginal secretions using single source and mixed reference samples. Finally, he will assess the accuracy, reproducibility, and sensitivity of the assay using developmental validation and casework-type samples.

This work has the potential to significantly improve the accuracy and sensitivity of forensic serological testing. It will provide practitioners with greatly improved tests for saliva and seminal fluid while also enabling the identification of vaginal secretions for which there are currently no accurate tests. The multiplex design will eliminate the need to perform separate tests on an unknown stain.

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