After these changes, we finally came up with the following optimised extraction procedure: 100 mg sample material (rapeseed, soya bean) or 200 mg sample material (corn) are weighed into 2-mL tubes. After addition of 1 mL, CTAB extraction buffer (2 % CTAB, 1.4 M NaCl, 0.1 M Tris, 20 mM EDTA, pH = 8.0) and 40 lL proteinase K solution, incubate samples at 65 C for 90 min while shaking at 850 rpm. Afterwards, a centrifugation step at 16,0009g for 10 min is performed. In case of insufficient sample separation, the centrifugation step must be repeated after transferring the clear supernatant to a new tube. Subsequently, 300 lL of the clear supernatant are transferred to a new tube and 300 lL lysis buffer (included in the kit) are added and mixed by vortexing (= sample mix). For each sample, a cartridge and an elution tube are placed in the rack. Pipette the sample mix and 100 lL elution buffer (included in the kit) into the first well of the cartridge and the elution tube, respectively. Plungers are placed in each cartridge before inserting the rack into the