The present invention is directed to a method of purifying a protein of interest from the particulate matter of a fermentation broth comprising the step of purifying the protein of interest from the particulate matter of the fermentation broth, wherein the step of purifying the protein of interest from the particulate matter of the fermentation broth comprises one or more washing steps, which comprises contacting the particulate matter with a washing solution comprising one or more conditions that favor the solubilization of the protein of interest and/or the desorption of the protein of interest from the particulate matter.