What is a multiplex bead assay?
Stimulation of blood or isolated cells results in the release of a cascade of biologically-related cytokines. For example, IL-6, TNF-alpha, and IL-1beta are involved in the inflammatory cascade, IL-2, IFN-gamma, and TNF-alpha characterize Th-1 cell activation, and IL-4, IL-5, and IL-10 are associated with a Th2 type response. A multiplex bead immunoassay permits the simultaneous measurement of an array of cytokines in a single, small volume sample. Using this method, it is possible to profile cytokine responses. The assay measures levels if a number of different cytokines in a single sample. How does the assay work? In this assay, the sample is cultured with distinct fluorescently labeled beads, coated with a cytokine-specific antibody. Beads specific for the different cytokines of interest are placed in a single tube with the sample. The capture antibody binds to the cytokine. Biotin-conjugated detection antibody specific for the cytokine of interest is then added, followed by fluores
