Development of a flow-through microscopic multitesting system for parallel monitoring of cell samples in biotechnological cultivation processes

The automated monitoring of cell variables in cultivation processes is a key technology in modern bioscience. In this article an innovative analytical tool for monitoring of cell densities in shaking-flask cultivations – consisting of a flow-through microscope with an automated image analysis software integrated in a FIA sampling system – is presented. This atline multitesting system was optimized by varying the height of the microscopes sampling zone. A calibration of the system was performed by correlating the FIA result peaks to known concentrations of Baker's yeast. It was successfully applied in cell density monitoring of cultivation processes of Saccharomyces cerevisiae with a good correlation with offline methods, and further used to monitor 3 parallel cultivations. This methodology was successfully transferred to Bacillus megaterium cultures and applied to measure the cell densities of parallel cultivation setups of B. megaterium and S. cerevisiae.