On-line detection of oxygen and pH at a small-scale can be used as a basis for latter cultivation in large-scale bioreactors to detect optimal growth conditions. Contamination-free on-line monitoring of culture parameters is not only important for scaling up production in process development, but it could also be valuable for other applications such as tissue engineering, stem cell research, and toxicological tests.
Suspension-adapted Chinese hamster ovary cell (CHO-S) cultures are widely used in biotechnological production of recombinant proteins. In fact, such special cell lines have become the standard for this type of biopharmaceutical production. The reasons for that include their fast reproduction, high protein expression rate compared with other eukaryotic cells and, above all, the glycosylation patterns generated by the cells. Efficient production of correctly processed proteins requires optimized cultivation parameters. The SensorDish® Reader (SDR) offers a non-invasive on-line detection method that for the first time enables quantitative characterization of both pH and oxygen in 24-well multidishes. From CHO-S cell cultures sampled in various start concentrations, a correlation can be demonstrated between cell number, oxygen consumption, and pH value during cell cultivation.