Cotton Swabs vs. 4N6FLOQSwabs®: A Comparative Study for Optimal Recovery of DNA
In forensic laboratories, moistened cotton swabs are often used to collect DNA evidence, but the dense inner core can trap cellular materials within its fibers (Image 1). An alternative type of swab, 4N6FLOQSwabsTM (Copan Italia, Brescia, Italy), is made of parallel short nylon strands that are flocked onto a plastic stick, which lack an inner core (image 1). This study was to compare DNA recovery of cotton and nylon flocked swabs from lymphocyte samples collected from various substrates, which have been shown to affect DNA yield, and to determine the best extraction method (1). A specialized spin basket, the Nucleic Acid Optimizer (NAOTM), has also been developed. It is a semipermeable basket that retains fluid until centrifuged, reducing the number of sample transfer steps reducing chances of contamination (2). The other objective of this study was to determine the effect of the NAOTM on nucleic acid recovery. 0 0.5 1 1.5 Blood on Glass Blood on Swab Blood in tube Average DNA Concentration (ng /µL) A) DNA Recovery from Blood Samples Blood directly in tube Nylon 0 2 4 6 8 10 12 14 16 Glass Leather Wood Plastic Metal Gun Grips Average Total DNA Recovered (ng) C) Nylon Flocked Swab vs Cotton Swab Recovery with PrepFiler® (NAO Used) Nylon Flocked Swab Cotton Swab swab, 4N6FLOQSwabsTM (Copan Italia, Brescia, Italy), is made of parallel short nylon strands that are flocked onto a plastic stick, which lack an inner core (image 1). Due to its design, it has been proposed that 4N6FLOQSwabsTM are also more effective at releasing cellular materials than cotton swabs. Thus, DNA release from blood samples on nylon flocked and cotton swabs was also performed. The 4N6FLOQSwabsTM are packaged and stored in sterile sample collector tubes and are treated with an antimicrobial agent (Image 2) . Another study was conducted to evaluate the antimicrobial activity of 4N6FLOQSwabsTM.