E05 478 566 350 170 or Enzyme-Linked Immunosorbent Assays,E05 478 566 350 170 or Enzyme-Linked Immunosorbent Assays,Immunoglobulin D (IgD) is an antibody isotype that makes up about 1% of proteins in the plasma membranes of mature B-lymphocytes where it is usually coexpressed with another cell surface antibody called IgM. IgD is also produced in a secreted form that is found in very small amounts in blood serum, representing 0.25% of immunoglobulins in serum for virus detection. Anti-viral immunoglobulin D antibodies have a diagnostic value.