Human CD200(Cluster of Differentiation 200) ELISA Kit  (E-EL-H2484)

This ELISA kit uses the Sandwich-ELISA principle. The micro ELISA plate provided in this kit has been pre-coated with an antibody specific to Human CD200. Standards or samples are added to the micro ELISA plate wells and combined with the specific antibody. Then a biotinylated detection antibody specific for Human CD200 and Avidin-Horseradish Peroxidase (HRP) conjugate are added successively to each micro plate well and incubated. Free components are washed away. The substrate solution is added to each well. Only those wells that contain Human CD200, biotinylated detection antibody and Avidin-HRP conjugate will appear blue in color. The enzyme-substrate reaction is terminated by the addition of stop solution and the color turns yellow. The optical density (OD) is measured spectrophotometrically at a wavelength of 450 nm ± 2 nm. The OD value is proportional to the concentration of Human CD200. You can calculate the concentration of Human CD200 in the samples by comparing the OD of the samples to the standard curve.

CD200 (OX-2) is a 45 kD cell surface glycoprotein that belongs to the immunoglobulin superfamily (IgSF). CD200 is composed of 202 amino acid extracellular domain containing two IgSF domains, 27 amino acid transmembrane segment, and a 19 amino acid cytoplasmic domain. CD200 is the only known ligand of the CD200R family and it is highly conserved in the CNS, expressed mainly by neurons and vascular endothelium. It is also present in most peripheral cell types, thymocytes, T and B cells, and dendritic cells. CD200 and CD200R interact with each other through N-terminal IgSF domains. Their interaction plays important roles in negatively regulating immune responses, and attenuating autoimmune diseases and excessive inflammatory responses against pathogens. High expression of CD200 in CNS is thought to be a mechanism of constitutive immune suppression, and is developmentally regulated in the mouse brain. Deficiency in neuronal CD200 may explain the chronic inflammation in human neurodegenerative diseases such as Alzheimer, Parkinson, and multiple sclerosis. CD200 and CD200R interaction has also been shown to play an important role in the regulation of anti-tumor immunity, and overexpression of CD200 has been reported in a number of malignancies, including CLL, as well as on cancer stem cells.