Comparative testing of weak anion exchange CIMmultus␢ DEAE chromatographic media was conducted in following work. During preparative pDNA purification pressure drop on the columns is often observed. It leads to prolonged process time and in extreme cases to irreversible column damage. Search for optimally channel diameter (2 µm, 3 µm, 6 µm) that would allow for efficient pDNA purification was the objective. Pressure drop and mass balance were two crucial parameters when evaluating different chromatographic media. Increased channel diameter leads to reduced dynamic binding capacity for target molecule. We expected plasmid size and oc isoform percentage are the drives of pressure drop. During testing of chromatographic columns with different channel diameters (2 µm, 3 µm, 6 µm) we aimed to determine optimal diameter that would allow for process without significant pressure drop and favourable mass balance. We confirmed starting hypothesis implying use of increased channel diameter when working with pDNA above 7 kbp. Column with 3 µm channel diameter was not optimal, when working with pDNAs above 7 kbp 6 µm channel diameter is advised. We confirmed oc isoform mediated pressure drop and column clogging due to oc isoform entrapment onto chromatographic surface.
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