Whole IgG antibodies are isolated as intact molecules from antisera by immunoaffinity chromatography. They have an Fc portion and two antigen binding Fab portions joined together by disulfide bonds and therefore they are divalent. The average molecular weight is reported to be about 160 kDa. The whole IgG form of antibodies is suitable for the majority of immunodetection procedures and is the most cost effective.-Based on immunoelectrophoresis and/or ELISA, the antibody reacts with heavy chain (HC) alpaca IgG, subclasses 2 and 3. It also reacts with HC llama IgG, subclasses 2 and 3. No antibody was detected against alpaca or llama IgG1, light chains or non-immunoglobulin serum proteins. The antibody reacts primarily with the Fc region, and is not recommended for detection of VHH antibodies. The antibody has been tested by ELISA and/or solid-phase adsorbed to ensure minimal cross-reaction with bovine, human, mouse, rabbit, and rat serum proteins, but it may cross-react with immunoglobulins from other species.