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Alexa Fluor 488

Alexa Fluor™ 488 (Ex-Max 490 nm/Em-Max 525 nm)

Alexa Fluor™ 488 (AF488, Alexa 488) has an excitation peak at 496 nm and an emission peak at 519 nm, and is considered a high-performance alternative to FITC. Alexa 488 is one of the most popular Alexa Fluor™ dyes and is widely used in Fluorescence Microscopy, flow cytometry, and for staining low expression markers. It is bright, highly photostable, resistant to pH changes, and less susceptible to photobleaching. Alexa 488 and is similar in size, brightness and application to DyLight™ 488, iFluor® 488 and CF®488A.

Excitation & emission spectra

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Key facts

Excitation maximum
496 nm
Emission maximum
519 nm
Optimal laser line
488
Optimal filter
530/43
Relative brightness
2 of 5
Extinction coefficient
71000
Quantum yield
0.92
Molecular weight
800
Commercial conjugates
4.6k from 32 suppliers

Alexa Fluor 488 has an excitation maximum at 496 nm and an emission maximum at 519 nm, a Stokes shift of 23 nm. Its extinction coefficient is 71000 M⁻¹cm⁻¹. It is optimally excited by the 488 laser line.

Frequently asked questions

What is Alexa Fluor 488?
Alexa Fluor™ 488 (AF488, Alexa 488) has an excitation peak at 496 nm and an emission peak at 519 nm, and is considered a high-performance alternative to FITC. Alexa 488 is one of the most popular Alexa Fluor™ dyes and is widely used in Fluorescence Microscopy, flow cytometry, and for staining low expression markers. It is bright, highly photostable, resistant to pH changes, and less susceptible to photobleaching. Alexa 488 and is similar in size, brightness and application to DyLight™ 488, iFluor® 488 and CF®488A.
What laser excites Alexa Fluor 488?
Alexa Fluor 488 is optimally excited by the 488 laser line. Its excitation maximum is 496 nm.
What filter should I use to detect Alexa Fluor 488?
A 530/43 filter captures the peak of the Alexa Fluor 488 emission near 519 nm with minimal spillover.
How bright is Alexa Fluor 488?
Alexa Fluor 488 has a relative brightness of 2 out of 5 (quantum yield 0.92).
How many antibodies are available conjugated to Alexa Fluor 488?
FluoroFinder tracks 4617 commercially available Alexa Fluor 488 conjugates, searchable by target, clone, host and application.