Principle of Assay
Human Surfactant Protein A/PSAP ELISA Kit (A2009) employs the sandwich enzyme immunoassay technique for the quantitative measurement of human Surfactant Protein A/PSAP in serum, plasma, tissue homogenates, cell lysates, lung lavage fluid, cell culture supernates or other biological fluids. An antibody specific for Surfactant Protein A/PSAP has been pre-coated onto a 96-well microtiter plate. The standards and test samples are added into the wells and the Surfactant Protein A/PSAP present in each sample is bound to the wells by the immobilized antibody. Following incubation, the wells are washed and then incubated with Biotinylated Anti-Surfactant Protein A/PSAP Antibody, which binds the captured Surfactant Protein A/PSAP present in each well. Following incubation, unbound biotinylated detection antibody is removed by washing, and an HRP-Avidin conjugate is added to the wells and the microtiter plate is incubated. Following incubation and washing, TMB substrate solution is then used to visualize the HRP enzymatic reaction by catalysis to produce a blue-coloured product that changes to yellow after addition of acidic stop solution. The density of yellow is proportional to the amount of Surfactant Protein A/PSAP captured in each well. The concentration of Surfactant Protein A/PSAP can then be calculated by reading the O.D. absorbance at 450nm in a microplate reader and referring to the standard curve.
