Principle and method of acridinium ester-labeled antigen-antibody complex
Principle of acridinium ester labeling
When the incident light of a certain wavelength passes through the antigen-antibody reaction solution, it is absorbed by the immune complex particles in it, and the immune complex particles absorb, reflect and refract. Within a certain range, the absorbance is correlated with the weakening of immune complexes, and the amount of immune complexes formed is positively correlated with the amount of immune complexes involved and the amount of antigens and antibodies involved in the reaction. The amount of antibody is positively correlated with antigen standards of known and known concentrations. The antigen content in the specimen can be determined by comparison with an antigen standard of known concentration.
Acridine ester labeling process:
After the antigen and the corresponding antibody are mixed in a certain proportion, with the extension of the reaction time, the total amount of immune complexes gradually increases, and the rate changes from slow to fast to slow, and the moment with the fastest reaction time is called the rate peak. When the amount of antibody in the reaction solution remains in excess, the height of the rate peak is proportional to the antigen content, and the instrument automatically converts the rate peak to the final concentration of the tested antigen through the standard curve.
Method evaluation of acridine esters
Advantages: high sensitivity, good stability, easy operation, accurate results
Deficiencies: ① The amount of antibody is relatively large; ② The antigen-antibody complex molecules in the solution should be large enough; ③ The second-stage measurement of the turbidimetric measurement in the antigen-antibody reaction needs to reach a balance in the antigen-antibody reaction. The reaction is carried out after the reaction reaches equilibrium, which takes a long time.
Marking Technology of Luminescent Agents
Direct coupling: The reactive group in the marker molecule is directly linked to the reactive group on the labeled molecule through a coupling reaction.
Indirect coupling: A chain or a group is inserted between the marker molecule and the target with a functional cross-linking agent, so that the two substances are linked by a "bridge" to form a conjugate. Advantages: increase the reactivity and reduce the steric hindrance effect. The marker maintains its own characteristics (antibody characteristics), and has marker characteristics (luminescence/catalytic luminescence)
Acridine ester-labeled chemiluminescence has the advantages of simple and rapid reaction, no catalyst, rapid luminescence, low background noise, and high sensitivity, but the luminescence time is short, and the requirements for signal monitors are relatively high. Desheng is one of the few acridines in China. Direct manufacturers of pyridine esters, welcome to consult and order.
When it comes to the chemiluminescent reagent Luminol, it is not unfamiliar to everyone and is commonly used in the field of criminal investigation to detect blood stains. Researchers have found that the principle of luminol luminescence can be used to detect specific substances in saliva, such as proteins, DNA, and related indicators of microorganisms, in order to determine physical conditions.