Fig. 1

a Schematic overview of the developed μRAMOS system for measuring the oxygen transfer rate in each single well. b Single well schematic cross section of the microfluidic MTP cover for OTR measurements. Valves, oxygen sensors, optical fibers, oxygen measuring instruments and capillaries are only shown for one well. All valves as well as the mass flow controller are controlled by a computer. The oxygen partial pressures of the headspaces of every well are detected via oxygen measuring instruments and monitored and analyzed by the computer. The MTP is mounted on an orbital shaker. The capillaries ensure an equal air flow through every well of the MTP. By applying overpressure through the pressure inlets, the elastic switching membrane seals the air inlet and outlet to realize an interruption of the air flow during the cultivation. The fluorescence sensor spot is glued onto the lower side of the cover facing the well headspace. The optical fiber is connected to an oxygen measuring instrument via an optical multiplexer on one end and plugged in the microfluidic cover facing the fluorescence sensor spot on the other end. Due to the transparent material, the oxygen dependent fluorescence behavior of the immobilized fluorescence spot can be excited and non-invasively detected through the material