The mean DNA yield per sample extracted from QIA and WAX. (A) A method based on UV absorbance at 260 nm. (B) Quantified using PicoGreen double-strand DNA-specific fluorescent dye. (C) Quantified using the quantitative polymerase chain reaction method. **P<0.01 vs. QIA. Data are presented as the mean ± standard deviations. QIA, QIAamp; WAX, WAXFree; UV, ultraviolet; Q41, the amount of DNA quantified using 41 bp primer pairs; Q129, the amount of DNA quantified using 129 bp primer pairs; Q305, the amount of DNA quantified using 305 bp primer pairs.