<unk>  <unk>  is a multimeric immunoglobulin, built of two heavy chains 
γ
{\displaystyle \gamma }
 and two light chains. Each complex has two antigen binding sites. This is the most abundant<unk> nd is approximately equally distributed in blood and in tissue liquids, constituting 75% of serum immunoglobulins in humans.
In birds,<unk>  is often called IgY, and is found in serum and yolk.
Immunoglobulin G
Immunoglobulin M
Immunoglobulin A
Immunoglobulin E
Immunoglobulin D
Gamma globulin
Light chain
Antibodies