Enhanced forensic DNA recovery with appropriate swabs and optimized swabbing technique

Efficient sampling with swabs is crucial for optimal forensic DNA analysis. The recovery determined by the skill of practitioner and compatibility between applied swab surface. Here we investigate impact swabbing technique type on yield. Thirteen different from four categories (cotton, flocked nylon, small foam large foam) provided equal yields smooth/non-absorbing surfaces. Large gave higher an absorbing wood Factorial design experiments ANOVA was to study techniques cotton swabs. Two key factors efficient were found be 1) holding approximate 60° angle against surface 2) rotate during sampling. For wood, it beneficial wet heavily. results factorial used develop protocols When ten experienced practitioners sampled according these protocols, yield increased ridged plastic (around 1.25 times more DNA) (2.2–6.2 DNA). window glass, representing a surface, protocol equivalent applying individual techniques. lowered person-to-person variation plastic. In conclusion, have developed instructive three types surfaces: smooth/non-absorbing, ridged/non-absorbing smooth/absorbing. We believe that such will streamline simplify training new improve efficiency invisible residues in casework.