Use of FITC as a Fluorescent Probe for Intracellular pH Measurement

Fluorescein Isothiocyanate (FITC) is widely used in biology and medicine as a fluorescent marker for labeling various proteins. Particularly fluorescence marking of antibodies could not be imagined without FITC. However, at the same time FITC displays pH-indicative properties. This paper evaluates the limits of the use of FITC as a pH indicator in biological material, namely, for intracellular and intraorganellar pH measurement.