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Rotational Platform-Driven Microdevice for Differential Separation, Purification, and Amplification of Sexual Assault Forensic Samples

NCJ Number
Date Published
January 2020
24 pages

This is the Final Summary Overview of a research project whose objective was to design a simple, inexpensive, microchip-based assay that can serve as an alternative to the laborious upstream work associated with sexual assault DNA sample processing.


This method replaces only the sample preparation, sperm/non-sperm cell separation, DNA purification, and multiplex-STR PCR amplification steps of the analytical process, resulting in ready-to-use DNA extract and amplicons that can move straight to an off-chip quantitation and separation/detection via methods   already validated and standardized in forensic laboratories. This approach minimizes costs and sample handling while reducing the labor time inherently extended for sexual assault samples that require a differential lysis process.  This project was based on a recently developed rotational device and previously described basic microchip architecture (FF Lucas Grant 2013, FSF Student Research Grant 2012) from this research group; however, several alterations and optimizations required completion for specific use with sexual assault samples. These alterations and optimizations are described in this report. A description of materials and methods addresses sample collection and preparation, the evaluation of custom prepGEM, antibody selection, antibody testing via flow cytometry, bead-mediated sperm cell capture, on-chip bead-mediated sperm cell capture (initial device), microdevice troubleshooting and modification, PowerPlex Fusion 5Custom STR chemistry, DNA quantification, amplification and separation through capillary electrophoresis, and STR data analysis. The project concludes that with additional optimization, validation, and subsequent commercialization, the sexual microdevice developed and described could have a significant impact on the forensic science community. Some of these impacts are noted in this report. 11 figures, 4 tables, and 9 references  

Date Published: January 1, 2020