Description
Introduction: Amyloid P component, serum (SAP) is the identical serum form of amyloid P component (AP), a 25kDa pentameric protein first identified as the pentagonal constituent of in vivo pathological deposits called "amyloid". AP makes up 14% of the dry mass of amyloid deposits and is thought to be an important contributor to the pathogenesis of a related group of diseases called the Amyloidoses. SAP is a member of the pentraxins family, characterised by calcium dependent ligand binding and distinctive flattened beta-jellyroll structure similar to that of the legume lectins. Human SAP has 51% sequence homology with C-reactive protein (CRP) Both SAP and CRP are evolutionary conserved in all vertebrates and also found in distant invertebrates such as the horseshoe crab.
Principle of the Assay: The microtiter plate provided in this kit has been pre-coated with an antibody specific to SAP. Standards or samples are then added to the appropriate microtiter plate wells with a 3 biotin-conjugated antibody preparation specific for SAP 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 SAP, 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 SAP in the samples is then determined by comparing the O.D. of the samples to the standard curve