Immunoglobulin A (IgA) is the predominant immunoglobulin in secretions and in the gastrointestinal and urogenital tracts. IgA makes up approximately 15% of serum immunoglobulins. IgA in serum is typically monomeric but dimeric in secretions (e.g., saliva, tears, colostrums, mucus, sweat, and gastric fluid) where it is found as a dimer connected by a J chain. IgA provides the primary defense mechanism against some local infections because of its abundance in mucosal secretions.
Two IgA subclasses exist in humans, IgA1 and IgA2, while mice have only one subclass. IgA1 is the prominent subclass of the total IgA concentration in human serum (~85%) with IgA2 representing approximately 15% of the total IgA in serum. IgA2 plays a critical role in the mucosa of the airways, eyes, and gastrointestinal tract to fight infectious antigens. SouthernBiotech produces and validates an extensive range of human and mouse IgA purified immunoglobulins available in unconjugated and conjugated formats, for use as standards and negative controls in applications such as ELISA, flow cytometry, immunofluorescence, and functional assays.