| Description | Complement C4 (C4) plays a central role in both the classical and lectin pathways of complement activation, with levels in human plasma ~0.4 mg/ml. C4 circulates in human plasma as a heterotrimer of 205,000 Da in plasma. The three disulfide-linked chains have molecular weights of 93 (alpha), 75 (Complement C4 (C4) plays a central role in both the classical and lectin pathways of complement activation, with levels in human plasma ~0.4 mg/ml. C4 circulates in human plasma as a heterotrimer of 205,000 Da in plasma. The three disulfide-linked chains have molecular weights of 93 (alpha), 75 (beta), and 32 (gamma) kDa. These are readily processed to create C4a, C4b or C4c depending on the processed state. Athens Research and Technology currently only sells the C4c form.Reacts to C4 antisera on Western BlotRef: Tack BF and JW Prahl. 1976. Biochemistry. 15:4513, Tack BF et al. 1981. Methods Enzymol. 80:64, Janatova, J. 1988. Methods Enzymol. 162:579... Read More | Inquire | p53 and MDM2 proteins-interaction-inhibitor (chiral) (Compound 32) is an inhibitor of the interaction between p53 and MDM2 proteins | Purity> 95 % by SDS-PAGE and HPLC analysesFunctionThis receptor has essential roles in the regulation of IgE production and in the differentiation of B-cells (it is a B-cell-specific antigen) | BackgroundStreptavidin is a tetrameric bacterial protein isolated from Streptomyces avidinii providing 4 high-affinity biotin binding sites. Streptavidin homo-tetramers have an extraordinarily high affinity for biotin. With a dissociation constant on the order of ≈10⁻¹⁴ mol/L,BackgroundStreptavidin is a tetrameric bacterial protein isolated from Streptomyces avidinii providing 4 high-affinity biotin binding sites. Streptavidin homo-tetramers have an extraordinarily high affinity for biotin. With a dissociation constant on the order of ≈10⁻¹⁴ mol/L, the binding of biotin to streptavidin is one of the strongest non-covalent interactions known in nature. Unlike egg-white avidin, which has a net positive charge at neutral pH and contains about 7% carbohydrate, streptavidin has almost no net charge at neutral pH, does not contain carbohydrate, and exhibits lower non-specific background. Streptavidin conjugates are widely used together with a conjugate of biotin for specific detection of a variety of proteins, protein motifs, nucleic acids and other molecules. This FITC-streptavidin conjugate was prepared by highly purified Streptavidin and free FITC was removed. Streptavidin (FITC) is a useful second-step reagent for the indirect immunofluorescent staining of cells in combination with biotinylated primary antibodies for flow cytometric analysis. Excitation at 488nm light leads to a fluorescence emission maximum of 520 nm.Recommended Usage：Every lot of Streptavidin-FITC is tested by flow cytometry using biotinylated primary antibodies. From this testing it is recommended that between 0.02 and 0.25 µg of streptavidin be used per 106 cells in a 100 µl staining volume... Read More |