NDSB 211 is a non detergent sulfobetaine that prevents protein aggregation and facilitates the renaturation of chemically and thermally denatured proteins. Most enzymes remain active in the presence of these reagents. The applications are wide ranging in protein biochemistry useful to enhance extraction, solubilization and crystalization. The non detergent sulfobetaine reagents are zwitterionic, very soluble in water ( greater than 2.0 molar), do not alter significantly the pH or viscosity of biological buffers and can easily be removed by dialysis.