The measurement of important parameters in the downstream process is still lax and there are no user friendly solutions that combine accuracy of results and ease of monitoring. To this aim, here we present a study using a mid infrared spectroscopy device, Monipa, to predict the concentration of different antibodies in various downstream processing steps, in collaboration with Alvotech. Monipa enables an easy to use real time monitoring using a single use flow cell and a simplified calibration model. Results indicate that the concentration of the mAbs can be accurately determined as compared to validated offline analytical methods, additionally a proof of concept for aggregation determination is presented.