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Cy3

Cy3 (Ex-Max 554 nm/Em-Max 568 nm)

Cy3 is an important historical fluorophore from GE Healthcare. It has an excitation peak at 554 nm and an emission peak at 568 nm. Spectrally its similar to Alexa Fluor™ 555.

Excitation & emission spectra

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Key facts

Excitation maximum
554 nm
Emission maximum
568 nm
Optimal laser line
532
Optimal filter
586/14
Relative brightness
1 of 5
Extinction coefficient
150000
Quantum yield
0.15
Molecular weight
627
Commercial antibodies
7.7k from 24 suppliers

Cy3 has an excitation maximum at 554 nm and an emission maximum at 568 nm, a Stokes shift of 14 nm. Its extinction coefficient is 150000 M⁻¹cm⁻¹. It is optimally excited by the 532 laser line.

Frequently asked questions

What is Cy3?
Cy3 is an important historical fluorophore from GE Healthcare. It has an excitation peak at 554 nm and an emission peak at 568 nm. Spectrally its similar to Alexa Fluor™ 555.
What laser excites Cy3?
Cy3 is optimally excited by the 532 laser line. Its excitation maximum is 554 nm.
What filter should I use to detect Cy3?
A 586/14 filter captures the peak of the Cy3 emission near 568 nm with minimal spillover.
How bright is Cy3?
Cy3 has a relative brightness of 1 out of 5 (quantum yield 0.15).
How many antibodies are available conjugated to Cy3?
FluoroFinder tracks 7671 commercially available Cy3 conjugates, searchable by target, clone, host and application.