CAS Registry Number

CAS 3326-32-7 — 5-Fluorescein isothiocyanate isomer I (FITC)

5-Fluorescein isothiocyanate isomer I (FITC) is a fluorescent dye used in bioconjugation for labeling proteins, antibodies, and other biomolecules in research and diagnostics. It exhibits strong fluorescence when excited by blue light. Available with CAS number 3326-32-7, molecular formula C21H11NO5S, and molecular weight 389.38 g/mol. Store at 2 to 8 °C. Hazard symbol: Danger. Molekula supplies FITC isomer I from research to bulk quantities with full documentation and ISO 9001:2015 traceability.