Merck, RAB0001-1KT, Human IgG ELISA Kit

Immunoglobulin G (IgG) belongs to immunoglobulin family, and consists of gamma (γ) heavy chain in the constant (C) region. IgG is a widely expressed serum antibody. Monomeric structure of IgG constitutes two identical heavy chains and two identical light chains with molecular weights of 50kDa and 25kDa respectively. The primary structure of this antibody also contains disulfide bonds linking the two heavy chains, linking the heavy and light chains, and are present inside the chains. IgG is further subdivided into four classes namely, IgG1, IgG2, IgG3, and IgG4 with different heavy chains, named γ1, γ2, γ3, andγ4, respectively. IgG is produced and released from CD5⁺B cells, the predominant lymphocytes in the neonatal cell repertoire. Maternal IgG is the only antibody transported across the placenta to the fetus. Maternal IgG passively immunizes the infants.