This assay employs the quantitative sandwich enzyme immunoassay technique. An antibody specific for ApoE has been pre-coated onto a microtiter plate. Standards or samples are pipetted into the wells and any ApoE present is bound by the immobilized antibody. After washing away any unbound substances, a biotin-conjugated antibody specific for ApoE is added to each well and incubate. Following a washing to remove unbound substances, streptavidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. After washing away any unbound antibody-enzyme reagent, a substrate solution (TMB) is added to the wells and color develops in proportion to the amount of ApoE bound in the initial step. The color development is stopped by the addition of acid and the intensity of the color is measured at a wavelength of 450nm ±2nm. The concentration of ApoE in the sample is then determined by comparing the O.D of samples to the standard curve. Sample Types: plasma, serum or other biological fluids. Range: 156 - 10000 pg/ml. Sensitivity: 200 pg/ml. Time: 4.5 hours ? Apolipoprotein E (ApoE) is a major apoprotein of the chylomicron. It binds to a specific liver and peripheral cell receptor, and is essential for the normal catabolism of triglyceride-rich lipoprotein constituents. This gene maps to chromosome 19 in a cluster with the related apolipoprotein C1 and C2 genes. Mutations in this gene result in familial dysbetalipoproteinemia, or type III hyperlipoproteinemia (HLP III), in which increased plasma cholesterol and triglycerides are the consequence of impaired clearance of chylomicron and VLDL remnants. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2014] Apolipoprotein E (ApoE) mediates the binding, internalization, and catabolism of lipoprotein particles. It can serve as a ligand for the LDL (apo B/E) receptor and for the specific apo-E receptor (chylomicron remnant) of hepatic tissues.