Scale-up protein separation on stainless steel wide bore toroidal columns in the type-J counter-current chromatography.

Manufacturing high-value added biotech biopharmaceutical products (e.g. therapeutic proteins) requires quick-to-develop, GMP-compliant, easy-to-scale and cost effective preparatory chromatography technologies.

Visualisation of J-type counter-current chromatography: a route to understand hydrodynamic phase distribution and retention.

This paper has addressed decade sought-after questions on phase bilateral distribution and stationary phase retention in any J-type high-speed counter-current chromatographic (CCC) centrifuge. Using a 2-D spiral column operated on such a CCC device and an aqueous two-phase system, this work systematically observed the phase interaction during transitional period and at dynamic equilibration under stroboscopic illumination. The experimental results thus obtained were used to examine the effects of the liquid-solid friction force, tangential centrifugal force, and physical properties of the two-phase system on hydrodynamic phase behaviour.

Improved g-level calculations for coil planet centrifuges.

Calculation of the g-level is often used to compare CCC centrifuges, either against each other or to allow for comparison with other centrifugal techniques. This study shows the limitations of calculating the g-level in the traditional way. Traditional g-level calculations produce a constant value which does not accurately reflect the dynamics of the coil planet centrifuge.

The three-dimensional model for helical columns on type-J synchronous counter-current chromatography.

Unlike the existing 2-D pseudo-ring model for helical columns undergoing synchronous type-J planetary motion of counter-current chromatograph (CCC), the 3-D "helix" model developed in this work shows that there is a second normal force (i.e. the binormal force) applied virtually in the axial direction of the helical column.

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.

A new non-synchronous preparative counter-current centrifuge-the next generation of dynamic extraction/chromatography devices with independent mixing and settling control, which offer a step change in efficiency.

A new and significantly more robust design of non-synchronous coil planet centrifuge is introduced where the degree of mixing between two immiscible phases can be changed independently from the "g" field required to separate out the phases. A hypothesis that an optimum ratio between the speed of the bobbin and the speed of the rotor can be found to optimise the efficiency of the separation for a given force field is upheld for an intermediate polarity phase system. This paves the way for extensive further research to find the optimum non-synchronous conditions for a range of different phase systems that are desirable for the separation of large molecules, proteins and biologics but can tend to emulsify in the standard "J" type centrifuge systems currently available and routinely in use for aqueous organic phase systems.

Continuous counter-current extraction on an industrial sample using dual-flow counter-current chromatography.

Both batch and continuous separations were performed on an industrial liquor using a specially built continuous counter-current extraction centrifuge. Changing the flow regime for different batch separations showed that the elution of components from the respective ends of the coil depends on the flow rates of both upper and lower phases. It was shown that, within the scope of the study, the elution of the components was not affected by the concentration of the injected reaction liquor and more importantly that continuous processing with a counter-current chromatography centrifuge was feasible.

Phase distribution visualisation in continuous counter-current extraction.

Flow visualisation is essential when trying to understand hydrodynamic equilibrium in continuous counter-current extraction (CCCE) (also known as dual-flow counter-current chromatography). The technique allows two immiscible liquid phases to be pumped through the spinning coil simultaneously in opposite directions. When this process was described previously it was assumed that the phases were evenly distributed throughout the coil.

Observations of established dual flow in a spiral dual-flow counter-current chromatography coil.

This paper describes the observations made in dual-flow counter-current chromatography. For the first time, the behaviour of the phases inside a spiral dual-flow coil has been studied using stroboscopic visualisation. During the study it was observed that the phase distribution and the linear flow rate in the tubing were not uniform throughout the coil, but behaved differently at each end of the coil with a transition area in between.