a minimum media plate to 5 ml culture medium and was then placed in a shaking incubator over night the next day 0 4 ml of the overnight culture was grafted to 40 ml of new culture medium the culture flask was again placed in the shaking incubator and the growth rate was controlled by withdrawing samples that were analysed with regard to absorbance at 600 nm at the absorbance 600 nm 0 4 the cultivation was interrupted the cells were centrifuged at 5000 g for 10 min the cell pellets were washed with 40 ml 0 05 m cacl 2 1 mm mncl 2 0 15 m nacl the cells were centrifuged for 10 m at 5000 g and the cell pellets were resuspended in 4 ml 0 05 m cacl 2 1 mm mncl 2 the following was added to a microtiter plate with 48 sample wells 10 u03bcl cell suspension was added and the samples were incubated for 10 min at room temperature in a shaking incubator then 0 05 m cacl 2 1 mm mncl 2 was added so that each sample had a final volume of 200 u03bcl incubation does not take place until all wells have been filled with the respective samples wells 7 16 1 u03bcl puc18 30 u03bcg ml as distributed in wells 1 6 above 10 u03bcl cell suspension and the samples were incubated for 10 min at room temperature in.