MEASURING METHOD OF ANTINEPHRITIS STRAIN ASSOCIATED PROTEIN ANTIBODY

PURPOSE:To measure the anti-NSAP antibody in serum by an enzyme immunoadsorption method by using an NSAP (nephritis strain associated protein)-carrier conjugate. CONSTITUTION:Extracellular protein (EPC) is obtd. from the A group streptococcus separated from an acute glomerular nephritis patient. The EPC is then dissolved and is subjected to preparative SDS-polyacrylamide gel electrophoresis and thereafter the gel is cut at 5mm width and 0.01M tris glycine buffer of 8.6pH is added thereto to homogenize the gel. The supernatant is dialyzed by ammonium hydrogencarbonate after centrifugal sepn. and the part corresponding to 46,000dalton mol.wt. in the sample is concentrated and the NASP is obtd. The NASP is diluted and is put into each hole of the carrier for conjugating the NSAP to form the NSAP-carrier conjugate. A peroxidase labeled antihuman IgG antibody is then diluted and is injected into each hole. The degree of color formation is measured by colorimetry and the antibody titer is determined.