Toyopearl and TSKgel 5PW resins, with the exception of some affinity resins, can withstand sanitization conditions commonly used in large scale manufacturing. A general used cleaning procedure is as follows: 3- 5 CV of 0.1-0.5 M sodium hydroxide, followed by 3-5 CV of 0.5-1 M sodium chloride before column equilibration. Toyopearl and TSKgel resins (with the exception of some affinity resins) can withstand caustic for well up to 8 hours at a time. Be sure to operate at reasonable flowrates to avoid over pressuring as the resin will swell in the presence of caustic. TOYOPEARL resins may be operated up to 6 bar and TSKgel PW-type resins may be operated up to 20 bar.
In some cases, protein may be tightly bound to the resin. In cases where protein is bound ionically, follow the hydroxide wash with 5 CV of water then 3-5 CV of 0.1-0.5 M hydrochloric acid before washing with salt. In cases where protein is bound hydrophobically to either HIC or SEC resin, wash the resin with 3-5 CV of water, followed by 3-5 CV of 20% methanol or acetonitrile. Rinse with 3-5 CV of water before following the general use cleaning procedure.
In regards to the affinity resins, the AF-Chelate resin may be cleaned following the general use cleaning procedure while the more ligand sensitive resins should be cleaned with any combination of salt, chaotrope (Urea/ Guanidine HCl), or detergents (Triton/ Tween). In extreme cases of tightly bound protein, the AF Heparin may be cleaned with 2 CV of 0.5 M sodium hydroxide as a last resort.