Cross-contamination control analysis of the automated DNA purification procedure on the BioRobot 9604. Samples (200 µl) of blood or water were added alternately to wells in the QIAamp 96 plate and the entire 96-well plate was processed following the QIAamp 96 DNA Blood BioRobot procedure. Five microliters of each 200 µl eluate was submitted to amplification in a 50 µl PCR using HotStarTaq DNA Polymerase, and the resultant products were analyzed on an agarose gel. No products were detected from eluates corresponding to wells containing water samples. Markers: Low DNA Mass Ladder (Gibco BRL).