Recovering DNA from fired cartridge casings (FCCs) and firearms (FAs) remains a significant challenge for forensic laboratories. The presence of heat, metal surfaces and trace-level DNA often results in poor yields, impeding successful DNA profiling. Yet, with firearm-related crimes on the rise, there is an urgent need to enhance recovery techniques and obtain interpretable genetic profiles from such difficult substrates.

This study explores the application of an automated, high-volume extraction protocol using the EZ2 Connect instrument to improve DNA yield from FCCs and FA swabs. DNA quantification was performed using the Quantiplex Pro RGQ Kit. Subsequent analysis employed capillary electrophoresis (CE) with the Investigator 24plex QS Kit and massively parallel sequencing (MPS) via the ForenSeq MainstAY Kit. Results showed that the optimized workflow increased both the quantity and quality of recovered DNA, enabling successful downstream typing.

A processing framework is proposed to support operational decision-making. It guides forensic analysts in selecting the optimal extraction and analysis strategy based on DNA concentration and degradation metrics. These findings highlight a path forward for improving DNA recovery from FCCs and FAs. Future work will focus on validating this workflow across additional firearm types and environmental conditions

About the speaker
Dr. Mirna Ghemrawi, Associate Director of Forensic Biology
The Center for Forensic Science Research & Education
Dr. Mirna Ghemrawi is the Associate Director of Forensic Biology at CFSRE and Program Director for the MS in Forensic Biology at Thomas Jefferson University. She holds a PhD in Biochemistry from FIU and has led numerous forensic research projects, contributing to peer-reviewed publications and international presentations. Her work focuses on advancing forensic DNA analysis by developing novel methodologies and exploring alternative biomarkers for forensic applications. A recipient of the MIT Innovators Under 35 award, she is also a reviewer for scientific journals and a dedicated advocate for STEM education, mentorship, and science communication​
Date of recording:Thursday, May 15, 2025
Duration:60 minutes
Categories
Webinar
Applied Testing Human ID
Forensic Casework
Next Generation Sequencing
Human ID & Forensics