Detection Method:Sandwich
Test principle:This assay employs a two-site sandwich ELISA to quantitate PZP in samples. An antibody specific for PZP has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and anyPZP present is bound by the immobilized antibody. After removing any unbound substances, a biotin-conjugated antibody specific for PZP 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 PZP bound in the initial step. The color development is stopped and the intensity of the color is measured.
Product Overview:Pregnancy zone protein (PZP), one of the major pregnancy-associated plasma proteins, was described by Smithies (1959) who used zone-electrophoresis in starch gels. PZP is a prominent constituent of late-pregnancy sera. In healthy, nonpregnant females and in males, PZP is present in trace amounts only: females, 10-30 mg/l; males, less than 10 mg/l. During pregnancy, PZP levels may reach 1000-1400 mg/l just before term. Sottrup-Jensen et al. (1984) showed that PZP closely resembles alpha-2-macroglobulin in structure. Both have a quaternary structure of 2 covalently bound 180-kD subunits which are further noncovalently assembled into a tetramer of 720 kD. Amino acid sequence of the 2 proteins are extensively homologous.
