Alexa (fluor)
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| Color | MW (amu) | Absorb (nm) | Emit (nm) | ε (cm-1M-1) | |
|---|---|---|---|---|---|
| Alexa Fluor 350 | blue | 410 | 346 | 442 | 19,000 |
| Alexa Fluor 405 | blue | 1028 | 401 | 421 | 34,000 |
| Alexa Fluor 430 | ylw-grn | 702 | 434 | 541 | 16,000 |
| Alexa Fluor 488 | green | 643 | 495 | 519 | 71,000 |
| Alexa Fluor 500 | green | 700 | 502 | 525 | 71,000 |
| Alexa Fluor 514 | green | 714 | 517 | 542 | 80,000 |
| Alexa Fluor 532 | red | 721 | 532 | 554 | 81,000 |
| Alexa Fluor 546 | red | 1079 | 556 | 573 | 104,000 |
| Alexa Fluor 555 | red | ~1250 | 555 | 565 | 150,000 |
| Alexa Fluor 568 | red | 792 | 578 | 603 | 91,300 |
| Alexa Fluor 594 | red | 820 | 590 | 617 | 90,000 |
| Alexa Fluor 610 | red | 1172 | 612 | 628 | 138,000 |
| Alexa Fluor 633 | not vis | ~1200 | 632 | 647 | 100,000 |
| Alexa Fluor 647 | not vis | ~1300 | 650 | 665 | 239,000 |
| Alexa Fluor 660 | not vis | ~1100 | 663 | 690 | 132,000 |
| Alexa Fluor 680 | not vis | ~1150 | 679 | 702 | 184,000 |
| Alexa Fluor 700 | not vis | ~1400 | 702 | 723 | 192,000 |
| Alexa Fluor 750 | not vis | ~1300 | 749 | 775 | 240,000 |
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 cell biology.
The excitation and emission spectra of the Alexa Fluor series cover the full range of the visible spectrum and extend into the infrared. The 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 other standard dyes of comparable excitation and emission. However, they tend to be more expensive.
Alternatives to Alexa Fluor dyes include Hilyte fluor dyes manufactured by Anaspec.
[edit] History
The Alexa Fluor dyes were named after Alex Haugland, son of the founders of Molecular Probes, Richard and Rosaria Haugland. The Marina Blue dye was named after their daughter, Marina.
[edit] External links
- Alexa fluor chapter and product highlight from the Molecular Probes/Invitrogen fluorescent probe handbook
- Early publication on Alexas: PMID 10449539
