Papers from cigarette butts or 3 paper disks per sample were spotted with 50 ng DNA per sample. After proteinase K digestion, the samples were incubated at 95°C for 5 minutes. Solid materials were removed from half of the samples, which were then processed using the EZ1 DNA Investigator Kit with the standard trace protocol (Trace). The remaining half of the samples was processed using the EZ1 DNA Investigator Kit with the "tip dance" protocol, without removing solid materials from the sample tubes (Tip dance). DNA yields were quantified by real-time, quantitative PCR.
AmpFlSTR control DNA (1 ng) was diluted in 200 μl Buffer G2 and purified using the EZ1 DNA Investigator Kit and the trace protocol on the EZ1 Advanced workstation. DNA was eluted in 50 μl water, and 10 μl (corresponding to 200 pg DNA) was used for STR analysis. PCR products were analyzed on an ABI PRISM 310 Genetic Analyzer with Genotyper software. (Data kindly provided by B. Bayer and K. Anslinger, Institute of Legal Medicine, Ludwig Maximilian University, Munich, Germany.)