250 mL were inoculated with 5 mL of preculture and incubated until they reached an OD of 0,5. After centrifugation, the cell pellet was washed with HTP buffer and resuspended in 3 mL HTP buffer. In the end, 225 µL DMSO was added to an end concentration of 6-7%. The 50 µL aliquots were frozen in N2(l) and stored at -80 °C.