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Table 1.8 Amine-reactive xanthene derivatives.

Fluorophore (Abs/Em) *COOHSuccinimidyl EsterOtherProtein and Nucleic Acid Labeling KitsNotes
Eosin (524/544)  E18 (ITC)5 
  • Useful for DAB photoconversion
  • Phosphorescent
Fluorescein (494/518)C1359 5
C1360 6
C1904 M		C2210 5
C6164 6
C1311 M
F6106 (X)6
F2181 (X)M
F6129 (X)M
F6130 (EX)5
C20050 (C)5		F143 (ITC)5
F1906 (ITC)5
F1907 (ITC)5
D16 (DTA)5		F6433 (F)
F6434 (F)
F10240 (P)
Z25042 (Z)
Z25342 (Z)
  • Most widely used green-fluorescent labeling dye
  • Absorption overlaps the 488 nm spectral line of the argon-ion laser
  • Prone to photobleaching
  • pH-sensitive spectra between pH 5 and pH 8
  • Common donor in FRET applications that utilize tetramethylrhodamine as the acceptor
JOE (520/548) C6171MP 6  
  • Traditional fluorophore used in automated DNA sequencing
  • pH-insensitive spectra at pH >6
Oregon Green 488 (496/524)O6146 5O6147 5
O6149 6
O6185 (X)6		O6080 MF6153 (F)
O10241 (P)
A10476 (APEX)
U21659 (U)
  • Photostable fluorescein substitute
  • pH-insensitive spectra at pH >6
  • Recognized by anti-fluorescein antibodies
Oregon Green 514 (511/530)O6138 MO6139 6  
  • Photostable fluorescein substitute
  • pH-insensitive spectra at pH >6
Rhodamine Green (502/527) R6107 M
R6113 (X)M		  
  • Photostable fluorescein substitute
  • pH-insensitive spectra
* The numbers in parentheses reflect the absorption (Abs) and fluorescence emission (Em) maxima, in nm, of the goat anti–mouse IgG antibody or dextran conjugates in aqueous buffer.

Superscripts 5, 6 and M correspond to 5-isomer, 6-isomer and a mixture of 5- and 6-isomers, respectively.

(APEX) = APEX Antibody Labeling Kit (Kits for Labeling Proteins and Nucleic Acids—Section 1.2).
(C) = Caged; the probe is nonfluorescent until the caging group is removed by UV illumination.
(COOH) = Carboxylic acid.
(DTA) = Dichlorotriazine.
(EX) = A seven-atom spacer that is more hydrophilic than X.
(F) = FluoReporter Protein Labeling Kit (Kits for Labeling Proteins and Nucleic Acids—Section 1.2).
(ITC) = Isothiocyanate.
(P) = Easy-to-Use Protein Labeling Kit (Kits for Labeling Proteins and Nucleic Acids—Section 1.2).
(U) = ULYSIS Nucleic Acid Labeling Kit (Labeling Oligonucleotides and Nucleic Acids—Section 8.2).
(X) = Aminohexanoyl spacer separating the dye and SE.
(Z) = Zenon Antibody Labeling Kit (Zenon Technology: Versatile Reagents for Immunolabeling—Section 7.3).

For Research Use Only. Not for use in diagnostic procedures.