Real-time forensic DNA analysis at a crime scene using a portable microchip analyzer

Liu, Peng; Yeung, Stephanie H.I.; Crenshaw, Karin A.; Crouse, Cecelia A.; Scherer, James R.; Mathies, Richard A.

doi:10.1016/j.fsigen.2008.03.009

« Previous Next »Forensic Science International: Genetics
Volume 2, Issue 4 , Pages 301-309, September 2008

Real-time forensic DNA analysis at a crime scene using a portable microchip analyzer

Peng Liu
- UCSF/UC Berkeley Joint Graduate Group in Bioengineering, University of California, Berkeley, CA 94720, USA
Stephanie H.I. Yeung
- UCSF/UC Berkeley Joint Graduate Group in Bioengineering, University of California, Berkeley, CA 94720, USA
Karin A. Crenshaw
- Palm Beach County Sheriff's Office Crime Laboratory, 3228 Gun Club Road, West Palm Beach, FL 33406, USA
Cecelia A. Crouse
- Palm Beach County Sheriff's Office Crime Laboratory, 3228 Gun Club Road, West Palm Beach, FL 33406, USA
James R. Scherer
- Department of Chemistry, MS 1460, University of California, Berkeley, CA 94720, USA
Richard A. Mathies
- UCSF/UC Berkeley Joint Graduate Group in Bioengineering, University of California, Berkeley, CA 94720, USA
- Department of Chemistry, MS 1460, University of California, Berkeley, CA 94720, USA
- Corresponding author at: Department of Chemistry, MS 1460, University of California, Berkeley, CA 94720, USA. Tel.: +1 510 642 4192; fax: +1 510 642 3599.

Received 6 February 2008; received in revised form 10 March 2008; accepted 31 March 2008. published online 21 May 2008.

Abstract

An integrated lab-on-a-chip system has been developed and successfully utilized for real-time forensic short tandem repeat (STR) analysis. The microdevice comprises a 160-nL polymerase chain reaction reactor with an on-chip heater and a temperature sensor for thermal cycling, microvalves for fluidic manipulation, a co-injector for sizing standard injection, and a 7-cm-long separation channel for capillary electrophoretic analysis. A 9-plex autosomal STR typing system consisting of amelogenin and eight combined DNA index system (CODIS) core STR loci has been constructed and optimized for this real-time human identification study. Reproducible STR profiles of control DNA samples are obtained in 2h and 30min with ≤0.8bp allele typing accuracy. The minimal amount of DNA required for a complete DNA profile is 100 copies. To critically evaluate the capabilities of our portable microsystem as well as its compatibility with crime scene investigation processes, real-time STR analyses were carried out at a mock crime scene prepared by the Palm Beach County Sheriff's Office (PBSO). Blood stain sample collection, DNA extraction, and STR analyses on the portable microsystem were conducted in the field, and a successful “mock” CODIS hit was generated on the suspect's sample within 6h. This demonstration of on-site STR analysis establishes the feasibility of real-time DNA typing to identify the contributor of probative biological evidence at a crime scene and for real-time human identification.