Fluorescent dyes are substances that absorb light waves of a certain wavelength and emit light waves with a wavelength greater than that of the absorbed light. Most of them are compounds containing benzene ring or heterocyclic ring and with conjugated double bond. Fluorescent dyes can be used alone or combined into composite fluorescent dyes.
After absorbing ultraviolet or visible light, it can convert short-wavelength light into longer-wavelength visible light waves and reflect them, showing shining bright colors. For example, acid eosin, fluorescent yellow, mercurochrome, and some disperse dyes. Most of them are compounds containing benzene ring or heterocyclic ring and with conjugated double bond.
Fluorescent dyes can be used alone or combined into composite fluorescent dyes. Among them, the composite fluorescent dye is a fluorescent dye synthesized using fluorescence resonance energy transfer technology, which is composed of a donor and an acceptor fluorophore molecules that are very close and energy can be transferred between each other. The composite dye is excited at the excitation wavelength of the acceptor molecule and emits a photon at the emission wavelength of the donor molecule. The development of fluorescent dyes is very rapid. The fluorescent dyes developed for scientific research and clinical applications have basically covered the entire spectrum from ultraviolet to visible light and infrared.
Fluorescent dyes are often used in the preparation of fluorescent dye products, as well as whitening agents in washing powders, various fluorescent road marking paints for indicating signals, fluorescent marking clothing, etc.
Other uses of fluorescent dyes include: Leaking sewage systems including water and industrial pollutants, connecting systems, measuring liquids discharged from power plants, leaks in toilets, monitoring of illegally connected sewage pipes, studying flow and mapping, analyzing corrupt systems , In addition, it is also used for fiber fabric printing and dyeing, some special signs (such as dark symbols) and military tracking.
Fluorescent dyes, due to their high sensitivity and convenient operation, have gradually replaced radioisotopes as detection labels, and are widely used in fluorescence immunity, fluorescent probes, and cell staining. Including specific DNA staining for chromosome analysis, cell cycle, cell apoptosis and other related research. In addition, many nucleic acid dyes are very useful counterstaining agents in multicolor staining systems. They can be used as background controls to mark the nucleus to make the spatial relationship of the intracellular structure clear.
Fluorescence-labeled monoclonal antibody technology has expanded unlimited application space for flow cytometry in the research of cell membranes and various functional antigens in cells, tumor gene proteins and other fields. The fluorescent probe can be covalently bound to the monoclonal antibody through a protein cross-linking agent. The most commonly used dyes for immunofluorescence labeling are fluorescein isothiocyanate (FITC), phycoerythrin (PE), and AlexaFluor series dyes.
Nucleic acid fluorescent dye stains the nucleus by quantitatively measuring the fluorescence intensity emitted by the cell, and then the content of DNA and RNA in the nucleus can be determined, and the cell cycle and cell proliferation can be analyzed. There are a variety of fluorescent dyes that can stain DNA or RNA in cells. Commonly used DNA dyes include propidium iodide (PI), DAPI, Hoechst 33342, etc., and RNA dyes include thiazole orange and acridine orange.