Scale-up of protein purifications using aqueous two-phase systems: Comparing multilayer toroidal coil chromatography with centrifugal partition chromatography

Two different laboratory scale liquid–liquid extraction processes using aqueous two-phase systems (ATPS) are compared: centrifugal partition chromatography (CPC) and multilayer toroidal coil chromatography (MTCC). Both use the same phase system, 12.5% (w/w) PEG-1000:12.5% (w/w) K2HPO4, the same flow rate of 10 mL/min and a similar mean acceleration field of between 220 × g and 240 × g. The main performance difference between the two processes is that there is a continuous loss of stationary phase with CPC, while for MTCC there is not – even when sample loading is increased. Comparable separation efficiency is demonstrated using a mixture of lysozyme and myoglobin. A throughput of 0.14 g/h is possible with CPC despite having to refill the system with stationary phase before each injection. A higher throughput of 0.67 g/h is demonstrated with MTCC mainly due to its ability to tolerate serial sample injections which significantly reduces its cycle time. While CPC has already demonstrated that it can be scaled to pilot scale, MTCC has still to achieve this goal.