skip navigation

Add your conference to our Justice Events calendar


Register for Latest Research

Stay Informed
Register with NCJRS to receive NCJRS's biweekly e-newsletter JUSTINFO and additional periodic emails from NCJRS and the NCJRS federal sponsors that highlight the latest research published or sponsored by the Office of Justice Programs.

NCJRS Abstract

The document referenced below is part of the NCJRS Library collection. To conduct further searches of the collection, visit the NCJRS Abstracts Database. See the Obtain Documents page for direction on how to access resources online, via mail, through interlibrary loans, or in a local library.

  NCJ Number: NCJ 236739   Add to Shopping cart   Find in a Library
  Title: Holographic Optical Trapping in Forensic Research and Development: Application to Rape Kit Analysis
  Document URL: PDF 
  Author(s): Tania Chakrabarty Ph.D.
  Date Published: 2010
  Page Count: 67
  Annotation: This study examined a technology called holographic optical trapping (HOT) in order to determine its performance in separating sperm cells from epithelial cells in sexual assault samples prior to DNA analysis.
  Abstract: Findings of the study show that HOT offers a powerful alternative approach for separating sperm from epithelial cells, thereby reducing the DNA carry-over problem. Even without the automation of HOT for sperm separation, the time taken for separating sperm from epithelial cells is less than 5 hours, making it amenable for adoption by forensic crime laboratories in their analysis of sexual assault forensic cases. Current practice in most crime laboratories involves a two-step differential extraction process, a chemical process that differentially disrupts sperm and epithelial cells, thus releasing their DNA for downstream STR analysis. This process is time-consuming, labor intensive and commonly results in female DNA carry-over into the male fraction, which interferes with DNA analysis and criminal identification. Optical trapping is a well-established scientific technique that has been widely applied in cell biology to manipulate cells. It is a non-destructive method in which trapped cells can live and reproduce while being held in the traps for extended periods of time. The author’s company, Arryx, Inc. has developed a robust commercial research instrument that can simultaneously deploy and move multiple optical traps independently of each other in three dimensions, using the unique and patented Holographic Optical Trapping (HOT) technique. This technology could provide an automated means for separating spermatozoa from epithelial cells in sexual assault samples offering single cell resolution. The research described in this report focuses on various aspects of the technique and its use in handling sexual assault samples. Using mock forensic swabs, this research demonstrated the compatibility of optical trapping with PCR and STR analysis. 23 figures, 1 table and 28 references
  Main Term(s): Police policies and procedures
  Index Term(s): Evidence collection ; Evidence identification and analysis ; Suspect identification ; Blood/body fluid analysis ; Rape investigations ; NIJ final report
  Sponsoring Agency: National Institute of Justice (NIJ)
US Department of Justice
Office of Justice Programs
United States of America
  Grant Number: 2008-DN-BX-K123
  Sale Source: National Institute of Justice/NCJRS
Box 6000
Rockville, MD 20849
United States of America

NCJRS Photocopy Services
Box 6000
Rockville, MD 20849-6000
United States of America
  Type: Report (Study/Research)
  Country: United States of America
  Language: English
  To cite this abstract, use the following link:

*A link to the full-text document is provided whenever possible. For documents not available online, a link to the publisher's website is provided. Tell us how you use the NCJRS Library and Abstracts Database - send us your feedback.