Buffer vs. Swabs: Efficacy of Carrier Nucleic Acids in Robotic Extractions

Author(s)

Shawn CecilFollow

Abstract

This study compared the efficiency of two carrier nucleic acid methods, specifically using salmon sperm DNA (spDNA), in robotic solid-phase extractions of cotton swab samples. Robotic extractions reduce processing time and workload but result in substantially lower DNA recovery than manual organic extraction. This research tested 10 µg of spDNA being added to the lysis buffer or pre-treating the swabs with it before DNA was added. Both methods showed a significant increase in recovery compared to extractions with no carrier. In the buffer extractions, recovery ranged from 69.4% to 117.5% and the swabs being pre-treated ranged from 84.2% to 125.8% which were similar. Using statistical analysis, it was confirmed that there was no statistically significant difference between the two application methods. The addition of spDNA drastically increased recovery in robotic extractions, despite the application methods, giving more insight into the mechanisms of carrier use. It seems it’s more effective in the extraction process than the elution process. It also raised the recovery of robotic extractions to a level comparable to that of organic extractions. Adding spDNA to the buffer gives forensic labs a more cost-effective, time-saving, and ethically practical way to increase DNA recovery in robotic extractions.

Department

Biological Sciences

Major

Biology

First Advisor

Dr. Crystal Oechsle

First Advisor Department

Biological Sciences

Second Advisor

Dr. Julie Peterson

Second Advisor Department

Chemistry

Third Advisor

Dr. Hans Wildschutte

Third Advisor Department

Biological Sciences

Publication Date

Fall 12-7-2025

Repository Citation

Cecil, Shawn, "Buffer vs. Swabs: Efficacy of Carrier Nucleic Acids in Robotic Extractions" (2025). Honors Projects. 1089.
https://scholarworks.bgsu.edu/honorsprojects/1089