DNA was diluted in Buffer G2 to a final concentration of 50 pg/µl, and the indicated volumes were processed using EZ1 DNA Investigator Kit with the standard trace protocol (Trace) or the large-volume protocol (LV). All samples were eluted in 50 µl water, and 5 µl was quantified using real-time, quantitative PCR.
Papers from cigarette butts or 3 paper discs per sample were spotted with 10 ng DNA per sample. After proteinase K digestion, half of the samples were processed using the EZ1 DNA Investigator Kit with the "tip dance" protocol, without removing solid materials from the sample tubes (Tip dance). Solid materials were removed from the remaining half of the samples, which were then processed using the EZ1 DNA Investigator Kit with the standard trace protocol (Trace). DNA yields were quantified by real-time, quantitative PCR.
In addition to the standard trace protocol, an optional, fully automated "tip dance" protocol can be used, where the filter-tip moves back and- forth relative to the worktable platform while pipetting. This enables processing of solid materials, such as swabs, fabrics, blood discs, or cigarette butts, directly in the sample tube. There is no need for prior centrifugation to remove solid materials that could clog the tip.