Versatile modules enable automated multi-column purifications on the AKTA pure chromatography system

Protein purification processes in basic research using AKTA (TM) liquid chromatography systems are often limited to single sample injections and simple one-column purifications. Because many target proteins in structural biology require complex purification protocols the work easily becomes laborious. To streamline and accelerate downstream protein production, an ALIAS (TM) autosampler and a modular sample in-line dilution process coupled to ion-exchange chromatography were incorporated into the workflow to automate two of the most commonly performed purification strategies - ion-exchange to size exclusion and nickelion metal affinity to size exclusion. The chromatographic setup enabled purification of a large array of cytosolic and membrane proteins from small-scale expression cultures produced in insect cells necessary to develop and optimize isotope-labeling strategies for nuclear magnetic resonance spectroscopy applications, resulting in a reduction in experiment time of about 20% per run for both cytosolic and membrane protein purification schemes. However, when queuing multiple samples the throughput increased by 66% and 75%, respectively. In addition, a novel system configuration is presented, where two column valves can be operated independently. This allows for the design of purification loops to increase purity of the target protein. (C) 2020 Published by Elsevier B.V.