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The Physical Separation and Single Source DNA Profiling of Individual Mixture Components by RNA in situ Hybridization-Based Cell Type Identification

NCJ Number
Date Published
September 2017
12 pages
The goal of this project was to develop a novel strategy for the de-convolution of admixed non-distinguishable epithelial cell mixtures using RNA in situ hybridization for cell type identification prior to DNA profiling.

The identification of the cell type prior to analysis would permit a physical separation of cell type populations (or mixture components), resulting in single source DNA profiling and tissue source attribution (body fluid or tissue source of origin) for an individual DNA profile. This effort involved cell type identification by RNA in situ hybridization; the physical separation of mixture components after RNA-FISH/CISH cell type identification for single source DNA profiling; and validation of developed RNA-FISH/CISH assays for de-convolution of admixed samples. These efforts are described in this report. The initial results indicate that RNA ISH can be used to identify vaginal and possibly buccal cells from dried stains, thus identifying them prior to collection and DNA analysis. This approach may be more useful in specialized cases, but not necessarily routine use. As of the writing of this report, assay development had not reached the appropriate stage for formal validation experiments to be performed. Additional work will be conducted during the remaining performance period in order to possibly improve the robustness of the assay. Thus, it is not clear at this time whether this approach will be sufficiently robust for routine use in forensic casework. Additional work is required to refine and validate this approach before a determination can be made. 3 figures

Date Published: September 1, 2017