Microplate reader:
ELISA Reader is a special instrument for enzyme-linked immunosorbent test. It can be simply divided into two categories, semi-automatic and fully automatic, but their working principles are basically the same. Its core is a colorimeter, that is, the colorimetric method is used to analyze the content of antigen or antibody. ELISA measurement generally requires the final volume of the test solution to be less than 250ul, and the test cannot be completed with a general photoelectric colorimeter, so there are special requirements for the photoelectric colorimeter in the microplate reader.
principle
The microplate reader is actually a phase-changing photoelectric colorimeter or spectrophotometer, and its basic working principle is basically the same as the main structure and photoelectric colorimeter. The figure shows the working principle diagram of a single-channel automatic sampling microplate reader The light wave emitted by the light source lamp is transformed into a monochromatic light by the filter or monochromator, and enters the specimen under test in the plastic microporous pole. Part of the monochromatic light is absorbed by the specimen, and the other part is irradiated through the specimen. On the photodetector, the photodetector converts the different light signals of the specimen to be tested into corresponding electrical signals. The electrical signals are processed by pre-amplification, logarithmic amplification, and analog-to-digital conversion, and then sent to micro-processing The processor performs data processing and calculation, and finally displays the results by the display and printer. The microprocessor also controls the movement of the mechanical drive mechanism in the X direction and Y direction to move the microplate through the control circuit, so as to realize the automatic sampling detection process. The microplate reader is used to manually move the microplate for detection, so the mechanical drive mechanism and control circuit in the X and Y directions are omitted, so that the instrument is smaller and the structure is simpler.
Enzyme-linked immunosorbent assay method
Enzyme-labeled immunosorbent assay method is abbreviated as enzyme-labeled method. It is a kind of labeling technology. It is a sensitive, specific, rapid and automated modern technology developed from fluorescent antibody technology and isotope immunotechnology.
The basic principle of the enzyme labeling method is to combine the antigen or antibody with the enzyme gel-linking agent to form an enzyme-labeled antigen or antibody. This enzyme-labeled antigen or antibody can specifically react with the corresponding antigen or antibody on the solid-phase carrier or in the tissue, and is firm Ground binding to form immune complexes that still remain active. When the corresponding substrate is added, the substrate is catalyzed by the enzyme to show the corresponding reaction color. The color depth is directly proportional to the corresponding antigen or antibody content.
Because this technology is based on the antigen-antibody reaction and the high-efficiency catalysis of enzymes, it has a high degree of sensitivity and specificity and is a very vital immunological test technology.
