Fluorescein-5-thiosemicarbazide is used in labeling of cell-surface functional groups (glycophorins). It is a cell impermeant fluorescent probe useful for determining protein and peptide topology on the cell surfaceA compound used to label cell-surface functional groups Fluorescein-5-thiosemicarbazide is used in labeling of cell-surface functional groups (glycophorins). It is a cell impermeant fluorescent probe useful for determining protein and peptide topology on the cell surface A compound used to label cell-surface functional groups application： Fluorescein-5-thiosemicarbazide can be used as a fluorescent labeling reagent to label: Cell-surface functional groups (glycophorins) in the study of the effect of deoxygenation in the red blood cell membrane. Saccharides applicable in polysaccharide imaging in live cells. Chondroitin sulfate nanogels applicable in cell-specific drug delivery applications.