Integrated DNA purification, PCR, sample cleanup, and capillary electrophoresis microchip for forensic human identification

• NCJ Number: 307052
• Journal: Lab on a Chip Issue: 6 Dated: 2011
• Author(s): Peng Liu; Xiujun Li; Susan A. Greenspoon; James R. Schererb; Richard A. Mathies
• Date Published: 2011
• Grant Number(s): 2009-DN-BX-K180; 2007-DN-BX-K142
• Agencies: NIJ-Sponsored
• Publication Type: Research (Applied/Empirical)
• Award: Microchip Analyzer for Forensic Short Tandem Repeat Typing of Single Cells; Microfabricated Capillary Array Electrophoresis Genetic Analysis for Forensic Short Tandem Repeat DNA Profiling

Annotation

In this article, the authors provide details on the development of a fully integrated microdevice and process for forensic short tandem repeat analysis that enables rapid, sensitive, and reliable on-site forensic human identification.

Abstract

A fully integrated microdevice and process for forensic short tandem repeat (STR) analysis has been developed that includes sequence-specific DNA template purification, polymerase chain reaction (PCR), post-PCR cleanup and inline injection, and capillary electrophoresis (CE). Fragmented genomic DNA is hybridized with biotin-labeled capture oligos and pumped through a fluidized bed of magnetically immobilized streptavidin-coated beads in microchannels where the target DNA is bound to the beads. The bead–DNA conjugates are then transferred into a 250 nL PCR reactor for autosomal STR amplification using one biotin and one fluorescence-labeled primer. The resulting biotin-labeled PCR products are electrophoretically injected through a streptavidin-modified capture gel where they are captured to form a concentrated and purified injection plug. The thermally released sample plug is injected into a 14 cm long CE column for fragment separation and detection. The DNA template capture efficiency provided by the on-chip sequence-specific template purification is determined to be 5.4% using K562 standard DNA. This system can produce full 9-plex STR profiles from 2.5 ng input standard DNA and obtain STR profiles from oral swabs in about 3 hours. This fully integrated microsystem with sample-in-answer-out capability is a significant advance in the development of rapid, sensitive, and reliable micro-total analysis systems for on-site human identification. (Publisher Abstract Provided)