Immunoassay

In medicine and immunology, an immunoassay is an immunologic test that is a "technique using antibodies for identifying or quantifying a substance. Usually the substance being studied serves as antigen both in antibody production and in measurement of antibody by the test substance."

Classification

Immunoblotting

Immunoblotting is an "immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies."

• Western blotting

Immunosorbent Techniques

Immunosorbent techniques are for "removal by adsorption and subsequent elution of a specific antibody or antigen using an immunosorbent containing the homologous antigen or antibody"

• Enzyme-linked immunosorbent assay (ELISA). "An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed."
• Radioallergosorbent test
• Radioimmunoprecipitation assay
• Radioimmunosorbent test