Sample Collection System for DNA Analysis of Forensic Evidence: Towards Practical, Fully-Integrated STR Analysis

• NCJ Number: 236826
• Author(s): Eugene Tan
• Date Published: 2010
• Length: 45 pages
• Grant Number(s): 2008-DN-BX-K010
• Agencies: NIJ-Sponsored
• Publication Type: Report (Study/Research)

Annotation

This research developed a sample collection system for law enforcement agents to use in collecting, protecting, and documenting biological evidence; and it performed initial processing steps in a format compatible with rapid sample-in to results-out microfluidic DNA analysis.

Abstract

The sample collection system developed consists of an evidence-collection device (a collecting swab and accompanying tube for swab insertion) and a sample processing cartridge. This "Smart Cartridge" lyses cells, makes soluble and concentrates DNA, and transfers the DNA solution to a microfluidic biochip. The microfluidic biochip will process the DNA solution to generate purified DNA compatible with the requirements for STR analysis. The evidence-collection device is designed to accept blood, buccal cells, saliva, and cellular samples. Cotton, modified cellulose, foam, nylon, polyester, and rayon-tipped swabs were evaluated for reproducibility of cell collection, ease of collection, tolerance to collection, protocol, liquid absorption, and use in forensic applications. The Bode SecurSwab was selected for the sample collection system. Operation of the system requires the user to collect a swab sample, insert the swab into the collection tube, place the tube into the Smart Cartridge, and press a start button; no further intervention is required. The DNA generated by the sample collection system will then be transferred automatically to NetBio's fully integrated microfluidic biochip for STR typing, which will generate an STR profile in 45 minutes from sample introduction, with minimal operating requirements. Several approaches to the sample processing steps were evaluated, and those selected were integrated to develop an optimized Smart Cartridge. 25 figures and 13 references