ChromPure is our trade name for highly purified proteins from the serum of non-immunized animals. The purified immunoglobulins in this section therefore do not represent antibodies directed against any known antigens. ChromPure proteins are prepared by a variety of methods, including ion-exchange, gel-filtration, hydrophobic, dye-ligand, metal-affinity, and immunoaffinity chromatographies. F(ab')₂ (pepsin), Fab and Fc (papain) (see Figure 1), and Fab_µ and Fc_5µ (trypsin) fragments are purified from enzyme digests of highly purified, whole molecules. No contaminating whole molecules or undesired fragments are observed at a minimum protein concentration of 20 mg/ml when tested by immunoelectrophoresis against anti-whole serums, anti-immmunoglobulins (class-specific), or anti-fragment-specific antisera. However, these proteins are not guaranteed to produce monospecific antibodies when used for immunization. They are used primarily as experimental controls.

All unconjugated ChromPure proteins are supplied without preservatives or stabilizers, either freeze dried or as sterile liquids in phosphate buffer. All conjugated ChromPure proteins are freeze dried in phosphate buffer containing preservatives and stabilizers.