company news about What conditions should the chemiluminescent reagent used as a label meet?

In the field of modern bioanalysis and medical diagnosis, chemiluminescent immunoassay (CLIA) has become an indispensable detection method with its many advantages such as high sensitivity and strong specificity. As the core element of this technology, the performance of the chemiluminescent reagent used as a label directly determines the test results. Let's talk about the key conditions that the chemiluminescent reagent used as a label should meet.

1. Ability to participate in chemiluminescent reactions
1）. Reaction principle basis: Chemiluminescent reagents must have the inherent characteristics of being able to participate in chemiluminescent reactions, which is the root of the generation of detection signals. Take acridinium ester as an example. As a relatively ideal luminescent substrate, it can be oxidized by hydrogen peroxide in an alkaline environment to emit light. This redox reaction process involves the transfer of electrons, the breaking and formation of chemical bonds, and ultimately leads to the release of energy in the form of light. Specific functional groups in the molecular structure of chemiluminescent reagents, such as the active ester group in acridinium ester, are key sites for initiating reactions. They can interact specifically with oxidants to start the luminescence mechanism. Only with such reactivity can the chemiluminescent reagent generate light signals timely and accurately in the immunoassay system according to the specific binding event of antigen-antibody.

2）. Impact on detection sensitivity: The efficiency of the reagent in the chemiluminescent reaction is closely related to the sensitivity. High reactivity means that the luminescence process can be quickly started in the presence of a lower concentration of reactants to produce detectable light intensity. In clinical diagnosis, for the detection of some trace biomarkers, such as tumor markers and hormones, chemiluminescent reagents are required to be able to keenly capture the subtle changes caused by antigen-antibody binding, and even if the target content in the sample is extremely low, it can be reflected by a strong and stable luminescent signal. If the chemiluminescent reagent has poor reactivity, it may cause weak or unstable luminescence, making it difficult for the detection system to distinguish between signals and background noise, thereby missing important diagnostic information.

2. Reagents that can form stable conjugates after coupling with antigens or antibodies
The coupling of chemiluminescent reagents with antigens or antibodies is a key step in building an immunoassay system, and it is important to form a stable conjugate. This requires sophisticated chemical coupling technology. For example, chemical reactions between active groups, such as the condensation reaction between amino and carboxyl groups, the addition reaction between thiol and maleimide, etc., can be used to achieve covalent connection between the two. During the coupling process, the reaction conditions, including temperature, pH value, reagent concentration, etc., must be strictly controlled to ensure the selectivity and efficiency of the coupling reaction.
From sample collection, storage to detection, the conjugate needs to withstand the test of different environmental factors, such as temperature fluctuations, changes in solution pH, etc. If the conjugate is poorly stable, it may dissociate due to slight temperature changes during sample transportation, causing the chemiluminescent reagent to separate from the antigen or antibody, which will not only reduce the detection sensitivity, but also may cause false negative results.

3. High quantum effect and reaction dynamics are still retained after coupling
The quantum effect determines the efficiency of photon generation of the chemiluminescent reagent during the luminescence process. The reagent after coupling should retain as high a quantum effect as possible, that is, the number of photons generated per unit chemical reaction should be large. For some complex biological samples, there are many interfering substances, such as proteins, nucleic acids, metabolites, etc. These substances may absorb and scatter light, reducing the intensity of the detection signal. High quantum effect chemiluminescent reagents can highlight the target signal in such a complex environment with their own efficient photon generation ability, making it easier for the detection system to identify and quantify.

4. The physicochemical properties of the labeled object should not be changed or changed very little
Protecting the immunological activity of the labeled object is one of the core principles of the application of chemiluminescent reagents. The immunological activity of the antigen is the basis for its recognition and binding by specific antibodies, and the immunological activity of the antibody is related to its ability to accurately capture the antigen. Once the chemiluminescent reagent excessively changes the physicochemical properties of the labeled object during the coupling process, such as causing the conformation of the antigen to be distorted and the binding site of the antibody to be shielded, the affinity of the antigen-antibody will decrease, and even the immune response ability will be lost.