Enzyme Labeling Instrument (ELI) is a kind of widely used medical equipment for biological testing, using enzyme immunoassay to perform qualitative or quantitative analysis based on the presence or absence of color presenting material and the depth of color presenting according to the principle of enzyme labeling. This is a very vital immunological technology. It can be used for monoclonal antibody screening, coagulation fraction, antibiotic sensitivity test, and other analytical work that requires colorimetric analysis. The instrument is suitable for clinical testing, microbiology, epidemiology, immunology, endocrinology, and agricultural and forestry sciences. It is widely used in hospitals, blood stations, epidemic prevention stations, biological products and other departments.
China's health administrative department has clearly stipulated that the diagnosis of common hepatitis disease can not be carried out by visual inspection, and must be judged by enzyme labeling instrument. There is no enzyme marker or do not use the enzyme marker hospitals can not be on the level, and no qualifications and rights to judge hepatitis. For the judgment of the spreading trend of HIV, must establish a special AIDS laboratory and the use of enzyme labeling instrument for judgment.
Classification
Enzyme labeling instrument is a commonly used instrument in the laboratory, generally can be divided according to the different ways of filtering light and different functions.
I. According to the function of the division, the enzyme marker can be divided into light absorption enzyme marker, fluorescence enzyme marker, chemiluminescence enzyme marker and multi-function enzyme marker. Light Absorbance Enzyme Labeler is used to detect the absorbance of visible light and ultraviolet light. When a specific wavelength of light passes through a sample in a microplate, the light energy is absorbed, and the absorbed light energy is proportional to the concentration of the sample, which can be used for qualitative and quantitative testing. The detection technology of light absorption is mature, low cost and simple to operate, but the dynamic range is narrow, the sensitivity is relatively low and the specificity is not strong. Generally, visible light and ultraviolet light use tungsten lamp and deuterium lamp as the light source respectively, while the UV/visible enzyme labeling instrument is able to switch the two kinds of light sources to adapt to the needs of different measurement wavelengths.
Fluorescence enzyme marker is used for fluorescence detection. After the light of specific wavelength is irradiated on the sample calibrated by the fluorescent substance through the excitation grating, it will emit the emitted light with longer wavelength and reach the detector through the emission grating. The intensity of the fluorescence is proportional to the concentration of the sample. Fluorescence detection is highly sensitive, real-time, easy to use, and has a variety of detection modes, but it is susceptible to external interference, as the excitation light and the emitted light tend to interact with each other, interfering with the detection. Chemiluminescence is the self-luminescence from biochemical reaction, which can be divided into two types: glow type and flash type. Glow-type luminescence is long-lasting, stable, and can last for a period of time; flash-type luminescence is short, fast-changing, unstable, and requires the application of an autosampler. The number of photons emitted in chemiluminescence is proportional to the amount of sample, and chemiluminescence enzyme marker has very high sensitivity and wide kinetic range. Multifunctional enzyme marker is a collection of the above three enzyme markers, such as BioTek's Synergy H1/H4, which integrates two or three types of enzyme markers into one, and can simultaneously carry out light absorption, fluorescence and chemiluminescence detection, which is powerful, widely used, can be used as a platform for research, avoiding the duplication of the purchase of the first choice of the laboratory.
II. Based on the different ways of filtering light can be divided into filter-type enzyme markers and grating-type enzyme markers. Filter-type enzyme marker using filters for wavelength selection, the enzyme marker built-in filter wheel, you can choose the different wavelengths required for the test filters for spectroscopy, the full spectrum of light emitted by the light source through the filter, most of the light is filtered, leaving only the wavelengths permitted by the filter itself to pass through, so that you can get a specific wavelength through the filter. Filter wheel generally contains 4-6 pieces of filters, by choosing different filters can be obtained by different wavelengths, but the wavelengths obtained are fixed, subject to certain limitations, can not be obtained arbitrarily desired wavelengths, and the replacement of filters is more expensive. Generally, the fixed wavelength filters are 405, 450, 490, and 630 nm.
The grating type of enzyme labeling instrument has only been around for a little more than ten years, but it has developed rapidly and is now the mainstream enzyme labeling instrument. For example, BioTek's Synergy Mx/H1m, which uses a grating for spectroscopy, the full spectrum of light emitted by the light source passes through the grating, and then is spectroscopically separated by a series of slits distributed on top of the grating to obtain an arbitrary wavelength of light, with wavelengths that are continuously adjustable in increments of 1 nm, and a bandwidth-selective function. Grating enzyme labeling instrument is easy to use and flexible, you can select any wavelength of light through the software, and can be full-wavelength scanning, through the full-wavelength scanning can be obtained from the unknown sample absorption peaks, so as to achieve the purpose of detecting unknown samples, in the laboratory is very popular, you can carry out more experimental testing. Therefore, it is very popular in China at present. In addition, according to the number of channels, can be divided into single-channel enzyme labeling instrument and multi-channel two types, single-channel and automatic and manual two kinds of points.