Affinity chromatography selective filters

Ap tamers can be selected in various ways. The most frequently used approaches are affinity chromatography [21] and modified cellulose filtration [4,22]. The choice of method depends on the properties of the target (for example, its capability to be immobilized on a matrix or to be bound to modified cellulose filters) and the aim of selection. If the desired aptamers should, for example, bind molecules on the surface of intact cells, the selection scheme should employ these cells adhering to the surfaces of tissue culture flasks [23]. 

The resulting mixture is sent to microlilters to remove large quantities of wastewater, which passes through the filters. For this step, alternate separators, like gel filtration and an Acticlean Etox resin (by Sterogene) should be considered. The retentate from the filter, which contains tPA, other proteins, endotoxin, arginine hydrochloride, and some water, is sent to an affinity chromatography operation. Here, tPA is selectively adsorbed on a resin... 

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