Study on Extraction of Trace Biomarkers from Different Vectors by Flocking Swabs and Cotton Swabs

Objective

To compare the effect of the Medico flocking Swabs and cotton swab on extracting trace DNA .

Methods

Three kinds of pre—decontaminated carriers，glass，screwdriver and drawer’S handle，were used to contact volunteers’hands and 9 pairs of samples of human trace DNA (fi ngerprints on glass，exfoliated cells on screw drivers and drawer handles）were prepared ．DNA was extracted by either Medico Flocking Swabs and／or cotton swab from all the samples and analyzed with GeneMapper ID V 3．2 soft-ware．The DNA extract efficiency was jued by the quantity of the detected loci，the loss of allelic genes and the peak area．

Result

Medico DNA swabs were used to detect five micro-DNA samples, and four samples were detected effectively. Nine micro-DNA samples from the micro-DNA sample swabs were effectively detected.Cotton swabs The number of alleles lost in the group was significantly more than that of the Medico swabs, and the peak area was significantly lower than that of the 4N6 swabs.

Conclusions

Medico flocking swabs performed significantly better DNA extraction of the exfoliated cells on glass surface fingerprints, open surgical exfoliated cells, and drawer handles than cotton  swabs in this study.

Main reason:1 Flocking swabs utilize nylon fiber flocking to maximize D N A acquisition and elution efficiency. Unlike traditional cotton swabs, the nylon fiber structure of the swab is perpendicular to the substrate, leaving the entire sample area intact with no internal absorption. D N A does not scatter and retain, resulting in faster and more efficient elution.
2 flocking swabs on the sample adsorption and release ability is stronger, due to the particularity of the material and structure of the flock swabs, samples can be taken to absorb human exfoliated cells to a greater extent, in the sample digestion and digestion, the sample Micro-ingredients can also be highly efficient release, do not retain the trace composition within the flock swab. The traditional composite nano swab swab made of more absorbent fibers, in the digestion and digestion, the sample trace of the ingredients easily retained in the wound fiber mass, affecting DNA extraction