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. Alexa Fluor dyes can be conjugated directly to primary antibodies or to secondary antibodies to amplify signal and sensitivity or other biomolecules.
The excitation and emission spectra of the Alexa Fluor series cover the visible spectrum and extend into the infrared. The individual members of the family are numbered according roughly to their excitation maxima in nanometers.
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.[according to whom?] At the time that Molecular Probes was founded,[when?] such products were largely unavailable commercially. A number of fluorescent dyes that are now widely used were discovered and developed in the laboratories of Molecular Probes.—dyes such as Texas Red, Cascade Blue, Oregon Green, Marina Blue, and the Alexa Fluor family. The most famous of these, the Alexa Fluor family of dyes,[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. The Alexa Fluor dyes were named after Alex Haugland, son of Richard and Rosaria Haugland.
Molecular Probes was acquired in 2003 by Invitrogen, who worked to further expand the Alexa Fluor family by the addition of new dyes to fill gaps not covered in the emission spectrum. In 2008, Invitrogen and the Alexa Fluor product line became a part of the Life Technologies, after the Invitrogen merger with Applied Biosystems. 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.