Human Major Histocompatibility Complex Class II DQ Beta 1 (MHCDQb1) ELISA Kit
Principle of the Assay
The microtiter plate provided in this kit has been pre-coated with an antibody specific to MHCDQb1. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated antibody preparation specific to MHCDQb1. Next, Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. After the TMB substrate solution is added, only those wells that contain MHCDQb1, biotin-conjugated antibody, and enzyme-conjugated Avidin will exhibit a change in color. The enzyme-substrate reaction is terminated by the addition of sulphuric acid solution, and the color change is measured spectrophotometrically at a wavelength of 450nm ± 10nm. The concentration of MHCDQb1 in the samples is then determined by comparing the O.D. of the samples to the standard curve.
For Use with serum, plasma, and cell culture supernatants. For Research Use Only. Not for use in diagnostic procedures.
Target Information
Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route, where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules, and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments, exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides, autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs, other cells of the gastrointestinal tract, such as epithelial cells, express MHC class II molecules and CD74 and act as APCs, which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen, three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs, CD74 undergoes a sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells, the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal microenvironment has been implicated in the regulation of antigen loading into MHC II molecules, increased acidification produces increased proteolysis and efficient peptide loading.
GENE ID | 3119 |
SWISS PROT | P01920 |
SYNONYMS |
HLA-DQB1; HLADQb1; CELIAC1; HLA-DQB; IDDM1; HLA Class II Histocompatibility Antigen,DQ Beta 1 Chain |
Materials Supplied
Kit Components | 96 Wells Quantity/Size |
---|---|
Pre-coated, ready-to-use 96-well strip plate | 1 plate |
Plate sealer for 96 wells | 2 |
Standard |
2 tubes |
Diluent buffer | 1 bottle |
Detection Reagent A | 1 bottle |
Detection Reagent B | 1 bottle |
TMB Substrate | 1 tube |
Stop Solution | 1 tube |
Wash Buffer (30 ℅ concentrate) | 1 tube |
Product data sheet | 1 copy |
Storage
Storage | The TMB Substrate, Wash Buffer (30X concentrate), and the Stop Solution should be stored at 4°C upon receipt, while the other items should be stored at -20°C. |
Performance Characteristics
REPEATABILITY |
Intra-assay Precision (Precision within an assay): 3 samples with low, middle, and high-level MHCDQb1 were tested 20 times on one plate, respectively. |
SENSITIVITY | The minimum detectable dose was 0.116ng/mL. |
ASSAY RANGE | 0.312-20ng/mL |
SPECIFICITY | This assay has high sensitivity and excellent specificity for the detection of MHCDQb1. No significant cross-reactivity or interference between MHCDQb1 and analogs was observed. Note: Limited by current skills and knowledge, it is impossible to perform all possible cross-reactivity detection tests between MHCDQb1 and all analogs, therefore, cross reactivity may still exist. |