Provided herein are methods of reducing bioburden of (e.g., sterilizing) a chromatography resin that include exposing a container including a composition including a chromatography resin and at least one antioxidant agent and/or chelator to a dose of gamma-irradiation sufficient to reduce the bioburden of the container and the chromatography resin, where the at least one antioxidant agent and/or chelator are present in an amount sufficient to ameliorate the loss of binding capacity of the chromatography resin after/upon exposure to the dose of gamma-irradiation. Also provided are reduced bioburden chromatography columns including the reduced bioburden chromatography resin, compositions including a chromatography resin and at least one chelator and/or antioxidant agent, methods of performing reduced bioburden column chromatography using one of these reduced bioburden chromatography columns, and integrated, closed, and continuous processes for reduced bioburden manufacturing of a purified recombinant protein.