An Affinity-Free, Centrifugal Microfluidic System for Rapid, Automated Differential Extraction

• NCJ Number: 310049
• Author(s): James P. Landers
• Date Published: November 2024
• Length: 26 pages
• Grant Number(s): 2020-DQ-BX-0024
• Agencies: NIJ-Sponsored
• Publication Type: Report (Study/Research)

Annotation

This paper presents a new method for rapid, automated differential extraction of bodily fluids on an assortment of substrates for sexual assault forensic evidence.

Abstract

In this study, the authors propose a rotationally driven microfluidic system to evaluate biological fluid samples on an assortment of substrates. Their proposed system removes the need for external pumps and valves for fluid movement control, while avoiding the need for large, clunky, and costly robotic platforms for automation. They describe this option as an affordable, automated, self-contained, disposable centrifugal, microfluidic differential extraction (DE) device that offers an attractive, unconventional approach to standard automation techniques while directly addressing many of the limitations associated with traditional DE methods. The authors represent a group that specializes in rotationally driven systems. Forensic DNA analysts are routinely asked to evaluate samples from a variety of biological fluids on an assortment of substrates. The outcome of that analysis may play a critical role in narrowing a pool of suspects, determining paternity, or identifying an unknown decedent. One of the most common types of evidence received in a forensic laboratory is a Sexual Assault Evidence Collection Kit (SAECK), which is used to gather biological evidence from victims of sexual assault, battery, rape, and attempted rape. In recent years, much ado has been made concerning backlogged SAECKs. While effective and universally used, traditional DE processes are manually intensive, prone to poor sperm cell DNA recovery, and frequently fail to adequately eliminate non-sperm cell DNA; this, at least in part, contributes to slow laboratory turnaround times. Significant, affordable improvement of the DE process will require a combination of changes to both chemistry and technical execution of the automation process.