IgG (Immunoglobulin G) is the most abundant Ig isotype in serum and makes up approximately 80% of all serum Immunoglobulins. In mice the IgG subclasses are defined IgG1, IgG2a, IgG2b and IgG3. The IgG molecule consists of two heavy and two lights chains (κ and λ) resulting in a molecule with two arms for antigen binding. High levels of IgG antibodies are induced following the initial IgM response in a typical immune response to antigens.
