Purity >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie? Blue Staining. MW (observed): 65-75 kDa, reducing conditions. MW (theoretical): 49 kDa (monomer). The Recombinant Mouse CD200 Fc Chimera Protein from R&D Systems is derived from NS0. The Recombinant Mouse CD200 Fc Chimera Protein has been validated for the following applications: Binding Activity.