SENSOLUX® stand-alone version: noninvasive determination of pH and DO in shake flasks

phosphate-based buffer system (0.05 M per liter, pH 8.6, 0.15 M ion strength with NaCl). The temperature was controlled via the control unit at 37 °C, and data were detected with an interval of 6 s. We achieved a maximum deviation smaller than ±0.1 pH units with a Sartorius Stedim Biotech now introduces the SENSOLUX® technology, which enables an optical and noninvasive measurement of the pH value and the dissolved oxygen saturation (DO) during the cultivation of animal and human cells. The first member of this product line is the SENSOLUX® stand-alone, an intelligent shaker tray with an integrated sensor system. Used in combination with the new single-use SENSOLUX® Erlenmeyer Flasks (EF), it facilitates the easy, safe and highly informative online measurement of these crucial process parameters in incubation shakers. SENSOLUX® EF are equipped with two precalibrated sensor patches that are sensitive to pH and DO, respectively. The sensor system integrated into the tray monitors both parameters optically and noninvasively from outside the SENSOLUX® EF. The SENSOLUX® technology is based on the principle of fluorescence. The sensor patches contain fluorescent dyes that can be excited with light of a given wavelength. The SENSOLUX® shaker tray contains nine independent optical sensors. Optical fibers integrated into the shaker tray transmit light of a particular wavelength to the sensor patches; at the same time, they also transmit the luminescence response from the patches to a measuring amplifier. The characteristics and intensity of the light emitted is influenced by changes in the concentration of the parameters pH or DO, respectively (Fig. 1). We evaluated the SENSOLUX® technology under different conditions. Here we compare the accuracy of the pH and DO patches to that of standard pH and DO electrodes. We also analyze the cultivation of Chinese hamster ovary (CHO) cells by using the SENSOLUX® EF.