The use of fluorescent dyes and how to judge the brightness?

Fluorescent dyes refer to substances that absorb light waves of a certain wavelength and emit light waves of another wavelength greater than the absorption of light. Most of them are compounds containing benzene ring or heterocyclic ring and with a conjugated double bond. Fluorescent dyes can be used alone or combined into composite fluorescent dyes.

Industrial applications of fluorescent dyes

Fluorescent dyes are often used in the preparation of fluorescent dye products, as well as whitening agents in whitening detergents, various road marking paints used for indicating signals, fluorescent marking clothing, etc.

Other uses of fluorescent dyes include leaking sewage systems, water, and industrial pollutants, connecting systems, measuring liquids discharged from power plants, leaks in toilets, monitoring illegal sewer connections, studying flow, and mapping. In addition, it is also used for textile printing and dyeing, some special signs and military tracking, etc.

Scientific research applications of fluorescent dyes

Due to its high sensitivity and convenient operation, it has gradually replaced radioisotopes as detection labels and is widely used in fluorescence immunity, fluorescent probes, cell staining, etc. Including specific DNA staining, chromosome analysis, cell cycle, cell apoptosis, and other related research. In addition, many nucleic acid dyes are very useful stains in multicolor staining systems.


Fluorescence-labeled monoclonal antibody technology has expanded infinite 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 protein crosslinking agents. The most commonly used dyes for immunofluorescence labeling are fluorescein isothiocyanate, FITC, phycoerythrin, and so on.

Nucleic acid amplification testing

Nucleic acid fluorescent dye stains the cell nucleus and quantitatively measures the fluorescence intensity emitted by the cell to determine the content of DNA and RNA in the cell nucleus, and can analyze the cell cycle and cell growth. There are many kinds of fluorescent dyes that can stain DNA or RNA in cells. Commonly used DNA dyes include PI, DAPI, Hoechst 33342; RNA dyes include thiazole orange and acridine orange.

How to judge the brightness of fluorescent dyes?

Fluorescent dyes are an indispensable and important tool in scientific research such as cell biology, and the filter cube is a vital component in a fluorescence microscope. So how does the brightness of general fluorescent dyes compare?

The brightness of fluorescent dyes can be used to compare the fluorescent labeling effects of different fluorescent dyes, expressed by the relationship between the fluorescent signals of the negative and the positive cell population. However, the fluorescent signal of the negative cell population is related to many factors such as signal intensity, autofluorescence, non-specific staining, and electronic noise of the instrument.

The fluorescent dye staining index is half of the ratio between the difference between the average intensity of the positive cell population and the average fluorescence intensity of the negative cell population and the standard deviation of the fluorescence intensity of the negative cell population. Fluorescent dye staining coefficient is only related to the antibody clone and quality, the purity of the fluorophore is related to Quality, fluorescence modification ratio, laser line, and its power, long pass and bandpass filters, target cells, and other factors are related.

The dyeing index of fluorescent dyes is positively correlated with the brightness of fluorescent dyes, that is, the higher the brightness of the dye, the higher the dyeing coefficient.