Alexa Fluor dyes are a patented line of fluorophores that exhibit a wide range of absorption and emission spectra, having been designed to match the principal output wavelengths of common laser and arc-discharge lamp excitation sources. These probes are commonly utilized in laboratories around the world and are relatively photostable and pH-insensitive when compared with other more conventional and spectrally similar fluorochromes. Alexa Fluor dyes are also water soluble, eliminating the necessity of using organic solvents for labeling purposes. In addition to the basic lineup of reactive Alexa Fluor dyes, a series of Alexa Fluor dye-conjugated phalloidins are commercially available, as are primary and secondary antibodies and antibody fragments.

The culture of Indian Muntjac deer skin cells presented in the digital image above was labeled with DAPI to target DNA, as well as Alexa Fluor 568 conjugated to phalloidin to target the cytoskeletal filamentous actin network. In addition, an Alexa Fluor 488-concanavalin A conjugate was used to label residues found in glycoproteins, enzymes, and cell membranes. Images were recorded in grayscale with a QImaging Retiga Fast-EXi camera system coupled to an Olympus BX-51 microscope equipped with bandpass emission fluorescence filter optical blocks provided by Omega Optical. During the processing stage, individual image channels were pseudocolored with RGB values corresponding to each of the fluorophore emission spectral profiles.