Alexa Fluor 594-conjugated antibodies absorb light maximally around 591 nm and fluoresce with a peak around 614 nm. They are brighter, more photostable, and more hydrophilic than Texas Red conjugates. Alexa Fluor 594 conjugates are brighter than red-fluorescing conjugates, and they provide more color separation from green-fluorescing dyes than DyLight 549, Cy3, and TRITC conjugates. They are the best choice for immunofluorescence detection in the deep-red region of the visible spectrum.