The secretory component is a single chain glycoprotein which is synthesized principally by epithelial cells in mucous membranes and exocrine glands. It occurs both in a free form and as a subunit of the secretory immunoglobulin A (SIgA) molecule. It has a molecular weight of approximately 75,000 Daltons. The secretory component is attached to the immunoglobulin molecule during the secretion process. Its biological function has not been established although several possibilities for which there are varying degrees of support have been suggested. These possibilities include: protection of IgA against destruction by proteolysis, transport of IgA across the epithelial surface and attraction of circulating lymphocytes with surface IgA to mucous membranes. Secretory IgA is also present in circulating blood and high concentrations of SIgA or free secretory component are reported in patients with carcinomas and chronic infectious diseases. Human IgA accounts for approximately 20% of all immunoglobulins found in adult human serum. It consists of two heavy chains and two light chains. In serum it is usually found as monomeric but in secretions it exists as a dimer linked by a J-chain and associated by a peptide secretory component. Although IgA has been shown to have the usual antibody properties it is probably more important in secretions (saliva, colostrum, tears, nasal, bronchial and intestinal) where it has the role of creating an immune barrier against various microorganisms at exposedmucous surfaces. Monoclonal Anti-Secretory Component (IgA) may be used for quantitative determination of human secretory component or secretory IgA in various body fluids and immunohistochemical localization of secretory component in mucous membrane tissue.
Synonyms: Anti-Secretory IgA
Storage: -20C
Application: Indirect ELISA: a working concentration of 0.06-0.12 mug/mL is recommended using 5 mug/mL secretory human IgA for coating.
Other Notes: In order to obtain best results in different techniques and preparations we recommend determining optimal working concentration by titration test.