The Human secretory immunoglobulin A (SIgA) ELISA Kit is used to quantitatively measure the levels of SIgA in human saliva, urine, or tear. This assay employs the quantitative sandwich enzyme immunoassay technique, in which SIgA in the samples or standards are sandwiched between pre-coated SIgA antibody and HRP-conjugated antibody specific for SIgA. Following a wash to remove any unbound reagent, the TMB substrate solution is added to the wells and color develops in proportion to the amount of SIgA bound in the initial step. The color development is stopped and the intensity of the color is measured at 450 nm via a microplate reader. This kit displays many advantages, including sensitivity, specificity, precision, linearity, and recovery. The product instructions are access to more information.
SIgA is the main immunoglobulin on mucosal surfaces of humans and many other mammals. It presents the immune system's first line of defense against mucosal pathogens and mediates host protection and pathogen neutralization upon reaching the luminal side. It plays an important role in the protection and homeostatic regulation of intestinal, respiratory, and urogenital mucosal epithelia separating the outside environment from the inside of the body. This process is known as immune exclusion, which allows for the segregation of the inside of the body that needs to remain sterile from the outside world rich in antigenic stimuli including those present in air, liquid, and food. SIgA is also involved in avoiding opportunistic pathogens to enter and disseminate in the systemic compartment, as well as tightly controlling the necessary symbiotic relationship existing between commensals and the host.