ALEXA FLUOR

	Color†	Absorb (nm)	Emit (nm)	MM (g/mol)	ε (cm-1M-1)
Alexa Fluor 350	blue	346	442	410	19,000
— 405	violet	401	421	1028	34,000
— 430	green	434	541	702	16,000
— 488	green	495	519	643	71,000
— 500	green	502	525	700	71,000
— 514	green	517	542	714	80,000
— 532	green	532	554	721	81,000
— 546	yellow-green	556	573	1079	104,000
— 555	green	555	565	~1250	150,000
— 568	orange	578	603	792	91,300
— 594	orange-red	590	617	820	90,000
— 610	red	612	628	1172	138,000
— 633	not vis	632	647	~1200	100,000
— 647	not vis	650	665	~1300	239,000
— 660	not vis	663	690	~1100	132,000
— 680	not vis	679	702	~1150	184,000
— 700	not vis	702	723	~1400	192,000
— 750	not vis	749	775	~1300	240,000
↑ = approximate color of the emission spectrum ε = extinction coefficient

The 'Alexa Fluor' family of fluorescent dyes is produced by Molecular Probes, a subsidiary of Invitrogen. Alexa Fluor dyes are typically used as cell and tissue labels in fluorescence microscopy and cell biology.^[1]
The excitation and emission spectra of the Alexa Fluor series cover the visible spectrum and extend into the infrared.^[2] The individual members of the family are numbered according roughly to their excitation maxima (in nm).
Alexa Fluor dyes are synthesized through sulfonation of coumarin, rhodamine, xanthene (such as fluorescein), and cyanine dyes. Sulfonation makes Alexa Fluor dyes negatively charged and hydrophilic. Alexa Fluor dyes are generally more stable, brighter, and less pH-sensitive than common dyes (e.g. fluorescein, rhodamine) of comparable excitation and emission,^[3] and to some extent the newer cyanine series. Quantitative comparison of long-wavelength Alexa Fluor dyes to Cy dyes: fluorescence of the dyes and their bioconjugates, Berlier JE, Rothe A, Buller G, ''et al'', , , J. Histochem. Cytochem., 2003 However, they also tend to be more expensive.
Similar alternatives include the Hilyte Fluor series from AnaSpec and DyLight Fluors from Pierce (Thermo Fisher Scientific).

Contents

History

References

External links

History

The Alexa Fluor dyes were name after Alex Haugland, son of the founders of Molecular Probes, Richard and Rosaria Haugland. The ''Marina Blue'' dye was named after their daughter, Marina.

References

1. Alexa Fluor Dyes Spanning the Visible and Infrared Spectrum
2. The Alexa Fluor Dye Series
3. Alexa dyes, a series of new fluorescent dyes that yield exceptionally bright, photostable conjugates, Panchuk-Voloshina N, Haugland RP, Bishop-Stewart J, ''et al'', , , J. Histochem. Cytochem., 1999

External links

★ Molecular Probes Handbook of Fluorescent Probes

★ Additional data table with molecular structures