Description
Principle of the Assay: The principle of the double antibody sandwich ELISA is represented in Figure 1. In this assay the Beta 2-Microglobulin present in samples reacts with the anti-Beta 2-Microglobulin antibodies which have been adsorbed to the surface of polystyrene microtitre wells. After the removal of unbound proteins by washing, anti-B2M antibodies conjugated with horseradish peroxidase (HRP), are added. These enzyme-labeled antibodies form complexes with the previously bound B2M. Following another washing step, the enzyme bound to the immunosorbent is assayed by the addition of a chromogenic substrate, 3,3',5,5'-tetramethylbenzidine (TMB). The quantity of bound enzyme varies directly with the concentration of B2M in the sample tested; thus, the absorbance, at 450 nm, is a measure of the concentration of B2M in the test sample. The quantity of B2M in the test sample can be interpolated from the standard curve constructed from the standards, and corrected for sample dilution.
Background: Beta 2-Microglobulin (B2M) is an 11 kDA protein. It forms the subunit of the MHC class I molecule and associates with the outer membrane of many cells including lymphocytes. It is present in low levels in serum and urine of normal people, but at a higher concentration in patients with renal diseases, kidney transplants and various other inflammatory and infectious conditions