Optimizing the Performance of Chromatographic Separations Using Microfluidics: Multiplexed and Quantitative Screening of Ligands and Target Molecules

The optimization of chromatography ligands for the purification of biopharmaceuticals is highly demanded to meet the needs of the pharmaceutical industry. In the case of monoclonal antibodies (mAbs), synthetic ligands comprising multiple types of interactions (multimodal) provide process and economic advantages compared to protein‐based affinity ligands. However, optimizing the operation window of these ligands requires the development of effective high‐throughput screening platforms. Here, a novel microfluidics‐based methodology to perform rapid and multiplexed screening of various multimodal ligands relative to their ability to bind different target molecules is demonstrated. The microfluidic structure comprises three individual chambers (≈8 nL each) packed with different types of chromatography beads in series with the feed flow. An artificial mixture composed of immunoglobulin G (IgG) and bovine serum albumin, labeled with different thiol‐reactive neutral fluorescent dyes, is used as a model to quantitatively optimize the performance (yield and purity) of the separation. This approach can potentially be used as a predictive analytical tool in the context of mAb purification, allowing low consumption of molecules and providing results in <3 min. Furthermore, this versatile approach can potentially be extended not only with respect to the number of different resins and target molecules, but also for parallel analysis of multiple conditions.