A+B-[u- product+light. The excited state products generated by the reaction of reagents A and B, the excited state substances are unstable, and quickly transition to a lower energy state (such as the ground state), and at the same time emit energy in the form of light (usually visible light).
According to the mode of excited state substances, chemiluminescence reaction can be divided into products in which reactants react chemically in organic systems to directly produce excited States; The other is that the energy released by chemical reaction is obtained from the fluorescent substance which is easy to accept energy in the system, and then converted into excited state.
Synthetic peptides, genetic engineering for expressing antigens and various labeling techniques have matured and developed rapidly. Radioimmunoassay and enzyme immunoassay gradually replaced the traditional immunoprecipitation and immune agglutination, which greatly improved the sensitivity and specificity of detection.