The present disclosure pertains to methods for separating proteins from surfactants that comprise (a) adding an amount of denaturing buffer to a mixture comprising a protein and a surfactant thereby forming a denatured solution wherein the protein is denatured and (b) filtering the denatured solution with a molecular weight cutoff filter, thereby separating the protein from the surfactant and the denaturing buffer. The present disclosure also pertains to kits for forming such methods.