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Development of an Automated Holographic Optical Trapping Method for Sexual Assault Evidence Kit Analysis

NCJ Number
239225
Author(s)
Tania Chakrabarty, Ph.D.; Ryszard Duszak, Ph.D.; Matthew Runyon, Ph.D.; Byeong-Seok Chae, Ph.D.; Osuola Akinbiyi; Evan Tanner; Pamela Korda, Ph.D.
Date Published
December 2011
Length
60 pages
Annotation

This final report describes the development of an automated system for trapping DNA evidence for use in sexual assault evidence kit analysis.

Abstract

This report describes the results of research aimed at developing an automated system for trapping DNA evidence for use in sexual assault evidence kit analysis. The system combines two technologies - microfluidic and machine-vision technologies with holographic optical trapping (HOT). This method of analyzing evidence allows for human sperm to be separated from epithelial cells and other contaminants in the sample to address the problem of DNA from both the victim and the perpetrator being included in the amplification process, which yields a mixed profile rather than a unique profile to match the assailant. The report discusses the reasons for the research - to address the evidence analysis backlog and the DNA carryover issue, and the goals of the research - to improve cell separation techniques, incorporate microfluidics for higher throughput and reduced reagent cost, and automate the handling of samples. The report presents information on the key laboratory methods used in the development efforts as well as the results of the development efforts using these methods. The report shows that significant progress has been made towards the development of a commercially viable automated system for isolating cells and handling evidence. Directions for future research and development are discussed, along with implications for criminal justice policy. Tables, figures, and references