News

Cyanine dyes,Commonly used are Cy3, Cy5, etc., which can bind to intracellular proteins. The fluorescent properties of these dyes are similar to those of traditional fluorescein, but they are water-soluble, light stable, high quantum yield and insensitive to pH. It is often used for multiple staining. The maximum excitation wavelength of Cy3 is 570nm, and the maximum emission wavelength is 650nm. However, under the excitation of green spectral wavelength, Cy3 can also show red fluorescence. The maximum excitation wavelength of Cy5 is 649 nm, and the maximum emission wavelength is 680 nm. Because the maximum emission wavelength of Cy5 is 680nm, it is difficult to observe it with naked eyes, and it is impossible to use high-pressure mercury lamp as an ideal excitation light source, so it is not recommended to use Cy5 when using ordinary fluorescence microscope. The laser scanning confocal microscope is usually used to observe Cy5.