Fluorescein Avidin D, FITC, 5 mg, having an excitation at 495 nm and an emission at about 515 nm, is made from Vector Laboratories' highly purified Avidin D by a special labeling technique. This product has an optimal fluorochrome to protein ratio and is the reagent we recommend for routine immunofluorescence applications. Compared to conventional primary and secondary fluorescent labeling techniques, Fluorescein Avidin D can provide greater sensitivity and lower background staining. (For even higher sensitivity and specific applications, see Fluorescein Avidin DCS, Cell Sorting Grade, (Cat. No. A-2011-1).