Design and characterisation of microlitre scale chromatography for the comparison with preparative scale chromatography

• Main Author: Shapiro, M.
• Published: University College London (University of London) 2009
• Subjects: 660.6
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.625239

Ion exchange chromatography is a ubiquitous unit operation within bioprocessing. There are a large number of ion exchange resins, however there is limited time and material available for a full assessment. The work reported is primarily concerned with the microfluidic scale down of process chromatography. Microfluidic technologies offer the potential to investigate events occurring within the bed (such as adsorption profiles) that would be more difficult to observe in larger systems. In addition, the devices may be used for the investigation of adsorbent type, buffer type, pH, flowrate etc. by employing parallel architecture to increase throughput. To facilitate the objectives described above, the fluidic handling and detection system was characterised. For the packing of microfluidic chips to be relevant for comparison, it was necessary to analyse the quality of the packing. Plate calculations combined with 3 dimensional imaging using confocal microscopy were used. According to the plate calculations, the microfluidic column was poorly packed, however the 3 dimensional imaging allowed a full assessment of the packing contained within the microfluidic column. Both frontal and elution chromatography results were generated using the microfluidic chip. Useful breakthrough curves using lysozyme were produced which compared well with both laboratory scale curves and previously published data. The general rate model was then used to understand whether the microfluidic column's breakthrough curves could simulate laboratory scale curves. The results produced showed that a new model was required to further develop the simulation. Separations were achieved using the egg white protein system containing 3 proteins. Microfluidic column separations were achieved using both step and linear gradients. These separations compared favourably with laboratory scale separations, although the use of linear gradients would require further work, as they proved challenging to reproduce at the microfluidic scale. However, the separation generated was similar to the laboratory scale.