Detection Method:Sandwich
Test principle:This assay employs a two-site sandwich ELISA to quantitate IgG4 in samples. An antibody specific for IgG4 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and anyIgG4 present is bound by the immobilized antibody. After removing any unbound substances, a biotin-conjugated antibody specific for IgG4 is added to the wells. After washing, Streptavidin conjugated Horseradish Peroxidase (HRP) is added to the wells. Following a wash to remove any unbound avidin-enzyme reagent, a substrate solution is added to the wells and color develops in proportion to the amount of IgG4 bound in the initial step. The color development is stopped and the intensity of the color is measured.
Product Overview:Three closely linked loci (IgG1, IgG2 and IgG3) were thought to be responsible for the Gm specificities. Van Loghem et al. (1970) presented evidence on the linkage relationship of immunoglobulin markers (gamma 1, 2, 3, Am). A fourth IgG locus (gamma-G4) was identifiable in the cluster. Using a gamma-4 probe, Kirsch et al. (1982) assigned the IGH cluster to 14q32 by in situ hybridization. Bech-Hansen et al. (1983) found that an RFLP produced by BamHI is a marker for the heavy chain genes G2 and G4 and a gamma-pseudogene. Considerable linkage disequilibrium was found. Quantitative assessment of the degree of association between C-gamma RFLPs, Gm markers, and switch region RFLPs adjacent to C-mu and C-alpha-1 showed that the gamma-pseudogene is most tightly associated with G2, suggesting that it lies between A1 and G2.
