ELISA stands for Enzyme-linked immunosorbent assay. ELISA is a technology used to detect the presence of an antibody in a sample. In ELISA, an amount of an antigen is applied to a surface and then coated with a specific antibody. The antibody will bind to the antigen and then an enzyme is used to translate those bonds into a visually detectable signal. ELISA can be used in many different industries including immunology, pharmacy, and diagnostics. In clinical settings it is used to detect all kinds of proteins, hormones(including those with small molecular weight like steroid hormones), antibiotics or medicines, pathogen antigens, and purified antigens in order to detect antibodies in a sample. Although it started as a screening test for diseases like smallpox and HIV, it is useful in detecting the binding affinity of any type of antibody to a specified antigen. The principle behind the application combines the specificity of antibodies with the sensitivity of simple enzyme assays. ELISAs can provide a useful measurement of antigen and/or antibody concentrations. The ELISA assay itself is a pretty simple procedure. First a microtiter plate with wells is coated with an antigen, (making sure to block all unbound sites to prevent false positives), then an antibody is added to the wells. Next, a conjugated enzyme is added. Finally, the reaction between the substrate and enzyme is produced and seen as a colored product indicating a positive reaction. ELISA antibodies can be either monoclonal or polyclonal and have the same structure as any other antibody. ELISA antibodies are characterized by an ELISA detection limit. The lower the ELISA detection limit, the more improved the sensitivity and specificity of the antibody.

The 5HT3B receptor is one of several receptors for the neurochemical serotonin (5-hydroxytryptamine). Serotonin is a neurotransmitter and a hormone responsible for the regulation of satiety, hunger, mood, and sleep. Anti- 5HT3B antibody binds to this receptor in place of serotonin and can effectively block the binding of 5HT3B. The receptor itself is cation exclusive but otherwise is a comparatively non-selective ion channel. Defects in serotonin receptors can lead to disorders like depression, obesity, autism, and problems with sleep. The anti-actin antibody will react with all 6 known vertebrate isoforms of actin. This antibody is useful in cancer research or more specifically the apoptosis or death of receptors and ligands. It is also useful in research surrounding signal transduction between actins using crosslinking. Defects in the actin cause myopathy or severe muscular weakness.