About Immunoglobulin gamma, IgG, mouse monoclonal H&L chain clones or rabbit, goat polyclonal antibodies have 4 parts. There are 2 heavy chains, 2 light chains. The IgG antibody has 2 antigen binding sites. They represent 70% or more of serum antibodies. This antibody can be antigen purified or protein A or G purified. For storage sodium azide is added or you can call us to request azide free antibody preparations. These will need colder storage temperatures.