Fluorescein FAM

What We Offer

Fluorescein FAM

BOC Sciences is committed to providing customers with high-quality fluorescein dyes. We provide a variety of carboxyfluorescein series labeling compounds, which can be modified by introducing various chemical functional groups to suit various labeling conditions.


The phenomenon of bioluminescence is widespread in nature. Fluorescein plays a very important role in the phenomenon of bioluminescence. Fluorescein molecules have two resonance structures: lactone type and quinone type. The two benzene rings in the molecular structure of fluorescein are on the same plane, which is conducive to fluorescence. The hydrogen atoms in the fluorescein structure are replaced by other groups, which can produce a series of different fluorescein derivatives.

Fluorescein and its derivatives are important fluorescent probe materials, which belong to oxanthracene dyes. The fluorescence intensity varies with the change of pH.

Two resonance structures of fluorescein molecule Two resonance structures of fluorescein molecule


Fluorescein is one of the earliest, most economical and most common fluorescent dyes. As a widely used labeling reagent, fluorescein has large extinction coefficient and high fluorescence quantum yield, and can emit strong green fluorescence. Fluorescein is suitable for the 488 nm spectral line of argon ion laser. In addition, due to the good water solubility of fluorescein, there is no problem of protein precipitation when labeling proteins with fluorescein. Its weakness is poor light stability, high fluorescence quenching rate, strong sensitivity to pH and wide emission wavelength range. Fluorescein is mainly used in confocal laser scanning microscopy and flow cytometry. Fluorescein can be used for biological disease detection and DNA labeling.


Fluorescein itself does not contain specific active groups, and cannot meet the requirements of the ever-developing biological analysis and other application fields. By introducing different functional groups to modify the structure of fluorescein, the produced fluorescein derivatives can make up for the defects of fluorescein itself.

Carboxyfluorescein (FAM) is a kind of fluorescent derivative. FAM reacts quickly with amino groups and the product is stable. It is an important protein labeling reagent. FAM is also suitable for the 488 nm spectral line of argon ion lasers. It has a large extinction coefficient and a high fluorescence quantum yield, and is stable in water. FAM is mainly used for primer modification and DNA sequencing. It is also commonly used for PCR product quantification and nucleic acid probes.

5-FAM and 6-FAM are two isomers of carboxyfluorescein. 5-FAM is a green fluorescent reagent that can label peptides, proteins and nucleotides, and can also be used to prepare small fluorescent molecules. 6-FAM will be used for sequencing and labeling of nucleic acids.