Complement receptor type 2 (CR2), also known as C3DR or CD21, is a protein that in humans is encoded by the CR2 gene. It is mapped to 1q32.2. CR2 is involved in the complement system. It binds to iC3b(inactive derivative of C3b), C3dg, or C3d. CR2 is the membrane protein on B lymphocytes to which the Epstein-Barr virus (EBV) binds during infection of these cells. CR2, together with CD19, CD81, and CD225, forms the B-cell coreceptor complex, which lowers the activation threshold of the B-cell antigen receptor. Genetic variations in this gene are associated with susceptibility to systemic lupus erythematosus type 9 (SLEB9).
Sample Type:Cell culture supernates, serum and plasma (heparin, EDTA)
Intended Use:For quantitative detection of human CD21 in cell culture supernates, serum and plasma (heparin, EDTA).
Sensitivity:<20pg/ml
Range:0.78-50ng/ml
Specificity:Natural and recombinant human CD21
Test Principle:This human CD21 BioAssay™ ELISA Kit was based on standard sandwich enzyme-linked immune-sorbent assay technology. A monoclonal antibody from mouse specific for CD21 has been precoated onto 96-well plates. Standards(CHO, Ile21-71) and test samples are added to the wells, a biotinylated detection polyclonal antibody from goat specific for CD21 is added subsequently and then followed by washing with PBS or TBS buffer. Avidin-Biotin-Peroxidase Complex was added and unbound conjugates were washed away with PBS or TBS buffer. HRP substrate TMB was used to visualize HRP enzymatic reaction. TMB was catalyzed by HRP to produce a blue color product that changed into yellow after adding acidic stop solution. The density of yellow is proportional to the human CD21 amount of sample captured in plate.
Kit Components:96-well plate precoated with human CD21 antibody, 1Lyophilized recombinant human CD21 standard, 50ng/tube×2Biotinylated human CD21 antibody, 130ul (dilution 1:100)Avidin-Biotin-Peroxidase Complex (ABC), 130ul (dilution 1:100)Sample diluent buffer, 30mlAntibody diluent buffer, 12mlABC diluent buffer, 12mlTMB color developing agent, 10mlTMB stop solution, 10ml
Storage and Stability:Store powder at 4°C liquid at -20°C. Store other components at 4°C. Stable for at least 6 months For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
