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Alexa Fluor® Dyes—Across the Spectrum

With the wide range of Alexa Fluor® dyes there is something for every filter and many options for multiplex detection. This series of superior fluorophores:

Spans the near-UV, visible and near-IR spectrum (Figure 1, Table 1).
Are compatible with all common excitation sources (Table 2) and instruments
Can replace standard fluorophores for most applications (Table 3)
Produce the brightest and most photostable conjugates, for multiplexing and multicolor detection

Emission Spectra

Figure 1. Emission spectra for Alexa Fluor® dyes.

Table 1. Properties of Alexa Fluor® Dyes

Alexa Fluor® dye	Absorption max. (nm)	Emission max (nm)	Emission color*	Extinction coefficient**
Alexa Fluor® 350	346	442	Blue	19,000
Alexa Fluor® 405	401	421	Blue	34,000
Alexa Fluor® 430	433	541	Green/Yellow	16,000
Alexa Fluor® 488	496	519	Green	71,000
Alexa Fluor® 532	532	553	Yellow	81,000
Alexa Fluor® 546	556	573	Orange	104,000
Alexa Fluor® 555	555	565	Orange	150,000
Alexa Fluor® 568	578	603	Orange/Red	91,000
Alexa Fluor® 594	590	617	Red	73,000
Alexa Fluor® 610	612	628	Red	138,000
Alexa Fluor® 633	632	647	Far Red	239,000
Alexa Fluor® 635	633	647	Far Red	140,000
Alexa Fluor® 647	650	665	Near-IR***	239,000
Alexa Fluor® 660	663	690	Near-IR***	132,000
Alexa Fluor® 680	679	702	Near-IR***	184,000
Alexa Fluor® 700	702	723	Near-IR***	192,000
Alexa Fluor® 750	749	775	Near-IR***	240,000
Alexa Fluor® 790	784	814	Near-IR***	270,000
* Typical emission color seen through the eyepiece of a conventional fluorescence microscope with appropriate filters. Extinction coefficient at lmax in cm-1M-1. ***** Human vision is insensitive to light beyond ~650 nm; it is not possible to view near-IR fluorescent dyes.

Table 2. Common Fluorescence Excitation Sources

Source	Principal lines (nm)
Mercury arc lamp	366, 405, 436, 546, 578*
Xenon arc lamp	250-1000*
Tungsten–halogen lamp	350-1000*
Blue diode laser	405
Helium–cadmium laser	325, 442
Argon ion laser	457, 488, 514
Nd:YAG laser	532**
Helium–neon laser	543, 594, 633
Yellow diode laser	561
Krypton ion laser	568, 647
Red diode laser	635
* Continuous white-light source. ** Frequency-doubled principal line output.

Table 3. Alexa Fluor® Dye Equivalents of Common Dyes

If you are using	Try this Alexa Fluor® dye
AMCA, coumarin	Alexa Fluor® 350
Cy2, FITC (fluorescein)	Alexa Fluor® 488
Cy3, TRITC (rhodamine)	Alexa Fluor® 555
Rhodamine red	Alexa Fluor® 568
Texas Red	Alexa Fluor® 594
Cy5	Alexa Fluor® 647
Cy5.5, IR680	Alexa Fluor® 680
Cy7	Alexa Fluor® 750

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