In the field of in vitro diagnostics, both the chemiluminescence immunoassay CLIA and the immunofluorescence analysis IFA are commonly used detection methods, and ultimately both are detected by a photometer, but the principles of the two are essentially different.
Compared with radioimmunoassay, fluorescence immunoassay, and enzyme-linked immunoassay, chemiluminescence immunoassay has more advantages. It has the characteristics of high sensitivity, strong specificity, wide linear range, simple operation, and does not require very expensive equipment. Moreover, it is radiation-free, the marker has a long validity period and can be fully automated.
Chemiluminescence reagent acridinium ester
The difference between chemiluminescence immunity and fluorescence immunity:
Although both are luminescence reactions, the most intuitive difference is that chemiluminescence is the reagent's own luminescence, while fluorescence is irradiated with a light source (usually ultraviolet) and then emits light. The light-emitting principle of the two is different, so the detection results will also be different.
Chemiluminescence is the use of energy generated by a chemical reaction to induce energy level transitions to emit light, such as luminol detecting bloodstains; fluorescence is a photoluminescence phenomenon, and a light source must be provided to excite molecules to produce energy level transitions, and then emit light.
Chemiluminescence is less interference than fluorescence immunity:
When these two methods are used for immunoassay, the difference is obvious. Chemiluminescence does not require an external light source, and the background interference is small; while fluorescence requires an external light source. When detecting in the direction of the vertical light source, the protein, amino acid and other molecules in the biological sample will also be detected. Background fluorescence is generated, and the background is slightly higher. It is necessary to select appropriate fluorescent reagents and sample processing methods to reduce the influence of non-specific adsorption of proteins.
In the direct method, the antibody of each antigen must be fluorescently labeled, and the fluorescently labeled may affect the antibody titer or even become invalid. The indirect method only needs to make the corresponding antibody to the corresponding antigen, and then use the labeled secondary antibody to bind to it. It does not need to be fluorescently labeled for each antibody, and it has little effect on the titer of the primary antibody. The chemiluminescence interference is very small and the specificity is very high. The use of the whole method is restricted by the non-specificity of the chemical analysis itself. The development of magnetic bead materials has made the development of chemiluminescence technology more and more mature.
In the development of in vitro diagnostic reagents, Desheng has achieved success in both enzyme-linked immunoassay reagents and chemiluminescence reagents. Among them, six acridinium esters, luminol and isoluminol are all necessary reagents in chemiluminescence immunoassays. .
