Английская Википедия:Alexa Fluor
Шаблон:Short description Шаблон:Use dmy dates Шаблон:Multiple issues The Alexa Fluor family of fluorescent dyes is a series of dyes invented by Molecular Probes, now a part of Thermo Fisher Scientific, and sold under the Invitrogen brand name. Alexa Fluor dyes are frequently used as cell and tissue labels in fluorescence microscopy and cell biology.[1] Alexa Fluor dyes can be conjugated directly to primary antibodies or to secondary antibodies to amplify signal and sensitivity[2] or other biomolecules.Шаблон:Citation needed
The excitation and emission spectra of the Alexa Fluor series cover the visible spectrum and extend into the infrared.[3] The individual members of the family are numbered according roughly to their excitation maxima in nanometers.
History
Шаблон:More citations needed section Richard and Rosaria Haugland, the founders of Molecular Probes, are well known in biology and chemistry for their research into fluorescent dyes useful in biological research applications.Шаблон:According to whom At the time that Molecular Probes was founded,Шаблон:When such products were largely unavailable commercially.Шаблон:Citation needed A number of fluorescent dyes that are now widely used were discovered and developed in the laboratories of Molecular Probes.Шаблон:Citation needed—dyes such as Texas Red, Cascade Blue, Oregon Green, Marina Blue, and the Alexa Fluor family.Шаблон:Citation needed The most famous of these, the Alexa Fluor family of dyes,Шаблон:According to whom were designed to improve upon properties of previously developed biological fluorescent dye families, and solve some of the issues that they possessed.Шаблон:Citation needed The Alexa Fluor dyes were named after Alex Haugland, son of Richard and Rosaria Haugland.Шаблон:Citation needed
Molecular Probes was acquired in 2003 by Invitrogen,[4] who worked to further expand the Alexa Fluor family by the addition of new dyes to fill gaps not covered in the emission spectrum.Шаблон:Citation needed In 2008, Invitrogen and the Alexa Fluor product line became a part of the Life Technologies, after the Invitrogen merger with Applied Biosystems.Шаблон:Citation needed In 2014, Life Technologies was acquired by Thermo Fisher Scientific, who revitalized the Invitrogen name and brand, bringing the Alexa Fluor product line back under it.Шаблон:Citation needed
Dyes and chemistry
Шаблон:More citations needed section The Alexa Fluor dyes were chemically synthesized through sulfonation and additional chemical modifications made to the well known families of coumarin, rhodamine, and cyanine dyes, and to the xanthene family (of which the fluorescein, an industry-standard, is a part).Шаблон:Citation needed Sulfonation made the product Alexa Fluor dyes negatively charged and thus more hydrophilic and soluble than their parent dyes;Шаблон:Citation needed the additional modifications were aimed to improve dye performance in other areas.Шаблон:Citation needed For example, Alexa Fluor 488, a sulfonated and otherwise chemically modifiedШаблон:Clarify form of fluorescein, was designed to solve the well known issues of rapid photobleaching and pH-dependent fluorescent intensity characteristic of the dye fluorescein isothiocyanate.Шаблон:Citation needed
| Colour†[5] | Absorb (nm)[6] |
Emit (nm)[6] |
MM (g/mol)Шаблон:Citation needed |
ε (cm−1M−1)[6] |
Quantum Yield[7] | |
|---|---|---|---|---|---|---|
| Alexa Fluor 350 | Blue | 346 | 442 | 410 | 19,000 | - |
| — 405 | Blue | 401 | 421 | 1028 | 35,000 | - |
| — 430 | Green | 434 | 541 | 702 | 15,000 | - |
| — 488 | Green | 495 | 519 | 643 | 73,000 | 0.92 |
| — 500 | Green | 502 | 525 | 700 | 71,000 | - |
| — 514 | Green | 517 | 542 | 714 | 80,000 | - |
| — 532 | Yellow | 532 | 554 | 721 | 81,000 | 0.61 |
| — 546 | Yellow | 556 | 573 | 1079 | 112,000 | 0.79 |
| — 555 | Orange | 555 | 565 | ~1250 | 155,000 | 0.1 |
| — 568 | Orange | 578 | 603 | 792 | 88,000 | 0.69 |
| — 594 | Red | 590 | 617 | 820 | 92,000 | 0.66 |
| — 610 | Red | 612 | 628 | 1172 | 144,000 | - |
| — 633 | Far-red | 632 | 647 | ~1200[8] | 159,000 | - |
| — 635 | Far-red | 633 | 647 | - | 140,000 | - |
| — 647 | Far-red | 650 | 665 | 1155.06[9] | 270,000 | 0.33 |
| — 660 | Near-IR | 663 | 690 | ~1100 | 132,000 | 0.37 |
| — 680 | Near-IR | 679 | 702 | ~1150 | 183,000 | 0.36 |
| — 700 | Near-IR | 702 | 723 | ~1400 | 205,000 | 0.25 |
| — 750 | Near-IR | 749 | 775 | ~1300 | 290,000 | 0.12 |
| — 790 | Near-IR | 782 | 805 | ~1750 | 260,000 | - |
| † = approximate colour of the emission spectrum ε = extinction coefficient | ||||||
Comparison with other dyes
Шаблон:More citations needed section The Alexa Fluor series dyes are less pH-sensitive and more photostable than the original dyes (fluorescein, rhodamine, etc.) from which they were synthesized.Шаблон:Citation needed While extinction coefficients of each member of this line of dyes are known (see table), quantum yieldsШаблон:Clarify and life times Шаблон:Clarify are not.Шаблон:Citation needed Brightness comparisons are also generally favorable.Шаблон:ClarifyШаблон:Citation needed
Other commercial product lines provide alternatives to individual members of the line of Alexa Fluor Dyes.Шаблон:Citation needed Comparisons with other dyes are less consistent,Шаблон:Clarify and also even more "delicate",Шаблон:Clarify depending on the conditions and techniques used.Шаблон:EditorializingШаблон:Citation needed Such comparisons should be considered, depending on the conditions and techniques used, and the dye performance (signal, background, stability) needed.Шаблон:EditorializingШаблон:Citation needed
Specific comparison studies
- Alexa Fluor 647 dye compared to dye Cy5,Шаблон:Clarify} in an application involving conjugation to DNA.[10]
Further reading
- Шаблон:Cite book Database entries written by independent experts, on Alexa Fluor product numbers 488, 647, 680, 700, and 750, as well as other conjugated forms.
- Шаблон:Cite journal Review of a lipid visualization application of the Alexa Fluors.
- Шаблон:Cite journal Review of a set of fluors based on Alexa Fluor (AF) 488, for receptor binding studies. Article presents structures of AF488 and AF532, as well as a large set of other standard flurophores Cy5, Texas Red, EVOBlue, FITC, NBD, Dansyl, 1-Pyrene, and various Bodipy complexes.
References
External links
