A method for preparing plasminogen, the method comprising: (a) expressing a recombinant plasminogen using a recombinant expression system under an expression condition sufficient to produce a recombinant plasminogen inclusion body; (b) contacting the recombinant plasminogen inclusion body with a solubilization buffer under a solubilization condition sufficient to obtain a solubilized recombinant plasminogen inclusion body; (c) contacting the solubilized recombinant plasminogen inclusion body with a refolding solution under a refolding condition to obtain a composition comprising the recombinant plasminogen, wherein a PEG or ammonium sulfate is added to the refolding solution under a precipitation condition, wherein the refolding solution comprises the plasminogen and aggregated polypeptides, wherein the plasminogen is refolded plasminogen, wherein the precipitation condition is sufficient to precipitate all or a substantial portion of the aggregated proteins; (d) diafiltering the composition subsequent to step (c); (e) contacting the composition with a cation-exchange medium under an ionexchange condition that is sufficient for the cation-exchange medium to bind the recombinant plasminogen; (f) eluting the recombinant plasminogen captured by the cation-exchange medium to obtain a cation-exchange medium eluate comprising the recombinant plasminogen; (g) contacting the cation-exchange medium eluate with a first affinity medium under a first affinity condition that is sufficient for the first affinity medium to bind the recombinant plasminogen; and (h) eluting the recombinant plasminogen bound by the first affinity medium to obtain a plasminogen solution comprising the recombinant plasminogen. (a) expressing a recombinant plasminogen using a recombinant expression system under an expression condition sufficient to produce a recombinant plasminogen inclusion body; (b) contacting the recombinant plasminogen inclusion body with a solubilization buffer under a solubilization condition sufficient to obtain a solubilized recombinant plasminogen inclusion body; (c) contacting the solubilized recombinant plasminogen inclusion body with a refolding solution under a refolding condition to obtain a composition comprising the recombinant plasminogen, wherein a PEG or ammonium sulfate is added to the refolding solution under a precipitation condition, wherein the refolding solution comprises the plasminogen and aggregated polypeptides, wherein the plasminogen is refolded plasminogen, wherein the precipitation condition is sufficient to precipitate all or a substantial portion of the aggregated proteins; (d) diafiltering the composition subsequent to step (c); (e) contacting the composition with a cation-exchange medium under an ionexchange condition that is sufficient for the cation-exchange medium to bind the recombinant plasminogen; (f) eluting the recombinant plasminogen captured by the cation-exchange medium to obtain a cation-exchange medium eluate comprising the recombinant plasminogen; (g) contacting the cation-exchange medium eluate with a first affinity medium under a first affinity condition that is sufficient for the first affinity medium to bind the recombinant plasminogen; and (h) eluting the recombinant plasminogen bound by the first affinity medium to obtain a plasminogen solution comprising the recombinant plasminogen.