Working principle and development prospect of enzyme labeling instrument

Enzyme linked immunosorbent assay (ELISA) is a special instrument for enzyme linked immunosorbent assay It can be simply divided into two categories: semi-automatic and full-automatic, but its working principle is basically the same, and its core is a colorimeter, that is, to analyze the content of antigen or antibody by colorimetry In general, the final volume of Zui in the test solution is less than 250 μ L, which can't be measured with the general photoelectric colorimeter, so there are special requirements for the photoelectric colorimeter in the enzyme labeling instrument
In fact, the enzyme calibrator is a special photoelectric colorimeter or spectrophotometer, its basic working principle is basically the same as the main structure and photoelectric colorimeter The figure shows the working principle of an enzyme calibrator with single channel automatic injection The light wave emitted by the light source lamp changes into a beam of monochromatic light through the filter or monochromator, and then enters the specimen to be tested in the plastic microporous pole Part of the signal is absorbed by the sample, and the other part is irradiated on the photodetector The photodetector converts the optical signals of different strength of the sample to corresponding electrical signals The electrical signals are processed by pre amplification, logarithmic amplification, analog-to-digital conversion and sent to the microprocessor for data processing and calculation, and the results are displayed by the display and printer after Zui In addition, the process of automatic sample injection detection is realized by controlling the movement of mechanical driving mechanism in X direction and Y direction by controlling the circuit In other enzyme labeling instruments, the detection is carried out by manually moving the microplate, so x is omitted, The mechanical driving mechanism and control circuit in Y direction make the instrument smaller and simpler in structure Microporous plate is a transparent plastic plate specially used for placing the samples to be tested through pre packaging There are multiple rows of holes with uniform size on the plate, and corresponding antigens or antibodies are embedded in the holes Each hole on the microporous plate can hold a few milliliters of solution Light is an electromagnetic wave The wavelength of 100nm-400nm is called ultraviolet light The light between 400nm-780nm can be observed by human eyes The light greater than 780nm is called infrared light People can only see the color because the light is reflected by the object when it shines on it The reason why green plants are green is that most of them absorb red orange light and blue violet light, but they don't absorb and reflect green light, so they are green The principle of enzyme labeling instrument is to detect the absorbance of the measured object at a specific wavelength At present, many family planning stations in China have carried out enzyme-free testing projects, such as: hepatitis B five, AIDS testing, eugenics and eugenics series testing, hormone testing, etc In the past, most of them adopted the visual inspection method, and the results were lack of scientific basis For example, in a Toxoplasma test kit, the critical value is defined as the OD value of the negative control × 2.5 It is impossible to judge whether the reaction color of the sample hole exceeds the critical value by visual inspection It may be OK to compare the color between two holes with naked eyes, but it is impossible to compare whether the color of one hole is more than 2.5 times the color of the other hole Many institutions in China, such as the clinical test center of the Ministry of health and the family planning system, have repeatedly emphasized the importance of the enzyme-linked immunosorbent assay (ELISA) and required that the enzyme-linked immunosorbent assay (ELISA) reagent should be interpreted by the enzyme-linked immunosorbent assay (ELISA), and the enzyme-linked immunosorbent assay reagent quality control should also be measured by the enzyme-linked immunosorbent assay (ELISA), and provided the original data of the enzyme-linked immunosorbent assay (ELISA), while the kit instructions of various manufacturers are not allowed to be visually tested At the same time, the items of enzyme immunoassay are often some substantial infections and pathological changes (such as hepatitis, AIDS, eugenics and eugenics, etc.), the interpretation is more rigorous, and the disputes caused by misdiagnosis are difficult to deal with In addition, the detection of EIA reagents such as hepatitis C and HIV before operation is a necessary means to avoid the medical accident disputes caused by infection caused by blood transfusion, which is gradually adopted by many units.