Provided herein are methods of performing chromatography with gamma-irradiated chromatography resin that include providing a chromatography column including a gamma-irradiated chromatography resin; performing a first cycle of chromatography through the column, where the cycle includes exposing the chromatography resin to a denaturing buffer; and performing at least one additional cycle of chromatography through the column. Also provided are integrated, closed or substantially closed, and continuous processes for manufacturing of a recombinant protein that include the use of at least one chromatography column including gamma-irradiated chromatography resin, where the gamma-irradiated chromatography resin is exposed to denaturing buffer during each cycle in the process, and reduced bioburden buffer is used in the process.