Programmed death-ligand 1 (PD-L1), also known as cluster of differentiation 274 (CD274) or B7 homolog 1 (B7-H1), is a protein that in humans is encoded by the CD274 gene. PD-L1 is a 40kD type 1 transmembrane protein that has been speculated to play a major role in suppressing the immune system during particular events such as pregnancy, tissue allografts, autoimmune disease and other disease states such as hepatitis. Normally the immune system reacts to foreign antigens where there is some accumulation in the lymph nodes or spleen which triggers a proliferation of antigen-specific CD8+ T cell. The formation of PD-1 receptor / PD-L1 or B7. 1 receptor /PD-L1 ligand complex transmits an inhibitory signal which reduces the proliferation of these CD8+ T cells at the lymph nodes and supplementary to that PD-1 is also able to control the accumulation of foreign antigen specific T cells in the lymph nodes through apoptosis which is further mediated by a lower regulation of the gene Bcl-2. Sample Type: Cell lysates, cell culture supernates, serum, plasma (Heparin or EDTA). Intended Use: Sandwich High Sensitivity BioAssay(TM) ELISA kit for Quantitative Detection of Human PD-L1/B7-H1. Sensitivity: <12pg/ml Range: 62.5pg/ml-4000pg/ml Specificity: Recognizes natural and recombinant Human PD-L1/B7-H1. There is no detectable cross-reactivity with other relevant proteins. Test Principle: This Human PD-L1/B7-H1 BioAssay(TM) ELISA Kit was based on standard sandwich enzyme-linked immune- sorbent assay technology. A specific for PD-L1/B7-H1 has been precoated onto 96-well plates. Standards(Expression system for standard: NSO, Immunogen sequence: F19-R238) and test samples are added to the wells, a biotinylated detection specific for PD-L1/B7-H1 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 PD-L1/B7-H1 amount of sample captured in plate. Kit Components: 96-well plate precoated with anti-Human CD274 antibody, 1x plate Lyophilized recombinant Human CD274 standard, 2x10ng/tube Biotinylated anti-Human CD274 antibody, 1x130ul (dilution 1:100) Avidin-Biotin-Peroxidase Complex (ABC), 1x130ul (dilution 1:100) Sample diluent buffer, 1x30ml Antibody diluent buffer, 1x12ml ABC diluent buffer, 1x12ml TMB color developing agent, 1x10ml TMB stop solution, 1x10ml PBS washing buffer Powder for 1000ml, 1x buffer Storage and Stability: Store powder at 4C liquid at -20C. Store other components at 4C. Stable for at least 6 months For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
