SECRETORY IgA (sIgA) ELISA KIT
INTENDED USE
The Secretory IgA (sIgA) ELISA Kit Assay is intended for the quantitative determination of secretory IgA (sIgA) in saliva and stool. For in vitro diagnostic use only.
INTRODUCTION
Secretory IgA (sIgA) consists of two IgA monomers joined by the J-chain and an additional secretory component. It is secreted in plasma cells located in the lamina propia of mucosal membranes. Synthesis of sIgA is independent from the synthesis of serum IgA. This means that lack of serum IgA does not necessarily correlate with a lack of sIgA1. Secretory IgA is the major immunoglobulin in saliva, tears, colostrum, nasal mucous, mother’s milk, tracheobronchial and gastrointestinal secretes. It plays a major role in preventing adherence of microorganisms to mucosal sites, in activation of the alternative complement pathway and in activating inflammatory reactions. Newborns are provided with sIgA by mother’s milk and are passively immunized against gastrointestinal infections.
PRINCIPLE OF THE TEST
Secretory IgA (sIgA) ELISA Kit
This Secretory IgA (sIgA) ELISA Kit is intended for the quantitative determination of secretory IgA in stool and saliva. In a first incubation step, the sIgA in the samples is bound to polyclonal antibodies (rabbit anti human IgA), which are immobilized to the surface of the microtiter wells. To remove all unbound substances, a washing step is carried out. In a second incubation step, a Peroxidase-labeled conjugate (mouse anti-sIgA) is added which recognizes specifically the bound secretory IgA. After another washing step, to remove all unbound substances, the solid phase is incubated with the substrate, Tetramethylbenzidine (TMB). An acidic stop solution is then added to stop the reaction. The color converts from blue to yellow. The intensity of the yellow color is directly proportional to the concentration of secretory IgA. A dose response curve of the absorbance unit (optical density, OD) vs. concentration is generated, using the results obtained from the calibrators. Secretory IgA in the patient samples is determined directly from this curve.
Download Product Data Sheet