Figure 3: Workflow of sample preparation for the identification of microorganisms directly from positive blood cultures. 8 ml blood are transferred to a serum separation tube and centrifuged for 10min at 2,000 g. The supernatant (serum) is removed carefully. Then the bacterial pellet, located on the gel, is resuspended in 300μl deionized water and transferred to a micro tube. A second centrifugation step is applied followed by the formic acid extraction procedure and the preparation on the MALDI target plate.