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Selecting the right particle size:
At the last chromatographic step in the process train, the feedstock now contains a relatively high concentration of the target molecule with perhaps some select impurities or aggregates.
For the polishing step, highly efficient smaller particle sizes tend to be used. Also, more selective techniques such as hydrophobic interaction chromatography may be employed.
Many commercial Toyopearl and TSK-GEL PW bulk resin products are offered in particle sizes from 100µm to 20µm and have the same methacrylic polymer backbone. (Custom products have been synthesized on 15µm particles.) The selectivity of feedstock components remains the same regardless of bead size.
All Toyopearl resins with bead diameters of 35µm and larger are made to withstand operating pressures up to 3 bar.
All TSK-GEL PW resins with bead diameters of 30µm and smaller are made to withstand operating pressures up to 20 bar.
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