Table 3.

Currently used Food and Drug Administration-approved fluorescence probes.

Fluorescence probe	Excitation	Emission	Fluorescence type
Indocyanine green	780 nm	820 nm	Indocyanin green
Methylene blue (MB)	670 nm	690 nm	MB
5-Aminolevulinic acid (5-ALA)	380–440 nm	620 nm (alkaline pH) 634 nm (acid pH)	Porphyrin
Fluorescein sodium	494 nm	512 nm	Fluorescein
Folate	495 nm (folate-FITC)	520 nm (folate-FITC)	Fluorescein isothiocyanate (FITC)
IRDye800CW conjugate	775 nm	796 nm	IRDye800
IRDye700DX conjugate	680 nm	687 nm	IRDye700
Activatable probes	Various	Various	Various