Description
Introduction: Pulmonary surfactant is a surface-active lipoprotein complex formed by type II alveolar cells. The proteins and lipids that surfactant comprises have both a hydrophilic region and a hydrophobic region. Specific surfactant proteins, SP-A, SP-B and SP-C, closely associated with surfactant lipids, contribute to the surfactant properties of the phospholipids. SP-C is a 3.7 kDa protein found solely in the surfactant layer of the alveolo. SP-C has been found to have three primary functions: catalyze the formation of surface-associated three-dimensional structures at the air-liquid interface, assist in the transfer of lipids from the monolayer to form stacked multi-layer structures and act as protection against surfactant inactivation by serum proteins.
Principle of the Assay: The microtiter plate provided in this kit has been pre-coated with an antibody specific to SP-C. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated antibody preparation specific for SP-C and Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. Then a TMB (3,3',5,5' tetramethyl-benzidine) substrate solution is added to each well. Only those wells that contain SP-C, biotin-conjugated antibody and enzyme-conjugated Avidin will exhibit a change in color. The enzyme-substrate reaction is terminated by the addition of a sulphuric acid solution and the color change is measured spectrophotometrically at a wavelength of 450 nm +/- 2 nm. The concentration of SP-C in the samples is then determined by comparing the O.D. of the samples to the standard curve