An automated instrument for human STR identification: Design, characterization, and experimental validation

Abstract

The microfluidic integration of an entire DNA analysis workflow on a fully integrated miniaturized instrument is reported using lab-on-a-chip automation to perform DNA fingerprinting compatible with CODIS standard relevant to the forensic community. The instrument aims to improve the cost, duration, and ease of use to perform a "sample-to-profile" analysis with no need for human intervention. The present publication describes the operation of the three major components of the system: the electronic control components, the microfluidic cartridge and CE microchip, and the optical excitation/detection module. Experimental details are given to characterize the level of performance, stability, reliability, accuracy, and sensitivity of the prototype system. A typical temperature profile from a PCR amplification process and an electropherogram of a commercial size standard (GeneScan 500™, Applied Biosystems) separation are shown to assess the relevance of the instrument to forensic applications. Finally, we present a profile from an automated integrated run where lysed cells from a buccal swab were introduced in the system and no further human intervention was required to complete the analysis.

Capillary and Microchip Electrophoresis

“…These systems are based on microfluidic technology and CE, permit analyses to be completed within 60 to 90 min, and will facilitate identity testing in forensic science and other applications. Fully microfluidic approaches for the same tasks are in development [192,193]. Many robust and portable diagnostic devices for near patient, field, and crime site testing will emerge in the near future.…”

Forensic DNA Analysis

“…There has been progress on microfluidic devices ('lab on a chip') since this was first discussed in forensics over a decade ago (Horsman et al 2007). So far work on three more or less integrated platforms has been published (Giese et al 2009;Bienvenue et al 2010;Hopwood et al 2010;Hurth et al 2010;Liu et al 2011), with at least one more instrument under development by the company IntegenX (Butler 2011). The goal for a typical integrated system is to generate STR results for several samples in parallel in less than 3 hours.…”

Direct loading of polymer matrices in plastic microchips for rapid DNA analysis: A comparative study

“…The resolution obtained is suitable for human identification applications but the main advantages of the HEC/PVP formulation are its low viscosity and its capability to coat channel surfaces in one single filling step as both the coating and sieving functions are achieved by the same polymer solution so as not to require preconditioning the microchannel before loading the sieving matrix . This simplifies the integration of such disposable COC microchips into a DNA analysis workflow system to process DNA swabs as we have previously reported using borosilicate devices of similar architecture .…”