<unk>  <unk>  is an antibody isotype that makes up about 1% of proteins in the plasma membranes of immature B-lymphocytes where it is usually coexpressed with another cell surface antibody called IgM.<unk>  is also produced in a secreted form that is found in very small amounts in blood serum. Secreted<unk>  is produced as a monomeric antibody with two heavy chains of the delta (δ) class, and two Ig light chains.
Immunoglobulin D
Immunoglobulin E
Immunoglobulin G
Immunoglobulin A
Immunoglobulin M
Gamma globulin
Light chain
Immunoglobulin heavy chain