Antibody isotyping is a critical and beneficial aspect of hybridoma development. This kit can identify six immunoglobulin heavy chain isotypes and two light chain isotypes in mice: IgA, IgM, IgG1, IgG2a, IgG2b, IgG3, kappa chain and lambda chain. It can accurately and specifically identify which heavy and light chain of the hybridoma samples is producing and if it is monoclonal or not. This kit is a powerful tool to isolate and characterize each potential clone. Identification is essential since chemical and biological properties of the various classes are unique. They differ in their solubility and electrophoretic properties, susceptibility to cleavage enzymes, and reactivity with protein A. Determining the class and subclass of a monoclonal antibody is thus useful in planning the best immunoglobulin purification method.