As we all know, the domestic IVD market has a growing demand for immunoassays, and various types of immunoassays are emerging. Chemiluminescence, as a method with more accurate detection results, has gradually replaced ELISA immunoassays. According to the method, chemiluminescence can be divided into: direct chemiluminescence, enzymatic chemiluminescence, and electrochemiluminescence. Luminol and acridinium ester are used in enzymatic chemiluminescence and direct chemiluminescence, respectively. Today we will discuss the different applications of luminol and acridinium ester in chemiluminescence.
I Chemiluminescent enzyme immunoassay
Chemiluminescent enzyme immunoassay (CLEIA) is an enzyme-labeled immunoassay that uses a chemiluminescent agent as a substrate for an enzyme reaction. After two-stage amplification of enzyme and luminescence, it has high sensitivity. Peroxidase is used as a labeling enzyme, luminol is used as a luminescent substrate, and a luminescence enhancer is added to improve sensitivity and luminescence stability. The labeling enzyme used can also be alkaline phosphatase, the luminescent substrate is dioxetane phosphate, and the solid phase carrier is magnetic particles.
II Direct chemiluminescence immunoassay
Chemiluminescence immunoassay (CLIA) is a type of immunoassay that directly labels antigens or antibodies with chemiluminescence agents. Acridinium ester is an ideal luminescent substrate and can be oxidized by hydrogen peroxide in an alkaline environment to emit light. The chemiluminescent agent used as a label should meet the following conditions:
1. Can participate in chemiluminescence reactions.
2. Stable conjugate reagent after coupling with antigen or antibody.
3. After coupling, high quantum effect and reaction power are retained.
4. Should not change or rarely change the physical and chemical properties of the labeled substance, especially the immune activity.
The advantage of this method is that it is not affected by excitation light scattering or point difference. The figure below schematically shows the mechanism of direct chemiluminescence of the sandwich method. The figure below schematically shows the mechanism of direct chemiluminescence of the sandwich method.
III Overall, Luminol and acridine ester luminescent agents are commonly used luminescent agents. Luminol is used as an enzymatic chemiluminescent substrate together with horseradish peroxidase for indirect chemiluminescence with a maximum wavelength of 425nm. The characteristics of the reaction are: high sensitivity and good stability of the enzyme. However, the disadvantage is that the longer excitation time results in a relatively slow speed, which may obscure antibody reaction sites during the labeling process. Currently, Antu Biology and others are using this method. As a direct luminescent marker, acridine ester needs to be carried out under alkaline conditions containing H2O2. The maximum wavelength of light emission is 430nm. The reaction characteristics are: the luminescence system is simple and fast, and the luminescence is completed within 5s, and no catalyst is needed, but the acridinium ester is unstable in the buffer salt and easily hydrolyzed. The manufacturer using this system is Abbott.
Desheng Technology is a manufacturer specializing in raw materials for blood testing and in vitro diagnostic reagents, focusing on intensive cultivation in the field for 15 years. It can provide acridinium ester, luminol and its supporting reagents. The products have been verified by more than 100+ manufacturers, the quality is guaranteed, the difference between batches is small, and a full set of subsequent technical services are provided. Welcome to contatct us for further consultation. Tel: +86-711-3702650. Website: www.vacutaineradditives.com
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