Several fluorescent dyes are commonly used to label antibodies, each with specific excitation and emission characteristics: - Fluorescein Isothiocyanate (FITC): Emits green fluorescence. - Rhodamine: Emits red fluorescence. - Alexa Fluor series: Available in multiple colors and known for high brightness and stability. - Phycoerythrin (PE): Emits orange-red fluorescence.