Detection Method:Sandwich
Test principle:This assay employs a two-site sandwich ELISA to quantitate ICAM4 in samples. An antibody specific for ICAM4 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and anyICAM4 present is bound by the immobilized antibody. After removing any unbound substances, a biotin-conjugated antibody specific for ICAM4 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 ICAM4 bound in the initial step. The color development is stopped and the intensity of the color is measured.
Product Overview:The LW glycoprotein has recently been renamed ICAM-4 due to its similarity to intercellular adhesion molecule, although exactly which integrins bind to ICAM-4 is subject to controversy. The function of ICAM-4 is not fully understood but appears to be restricted to erythroid cells. During in vitro erythropoesis, LW appears at either the erythroid colony forming stage or later at the proerythroblast stage. A vital part of erythropoesis is the clustering of erythroblasts around bone marrow macrophages to form erythroblastic islands. The erythroblast is then able to remove its nucleus, which is in turn ingested and broken down by the macrophages, to become a mature erythrocyte. During this process ICAM-4 binds to VLA-4, an erythroblast binding site, on adjacent erythroblasts and to alpha integrins on macrophages to help stabilise the erythroblastic islands.
