Fluorescein and Derivatives

Fluorescein fluorophores have been the most common fluorescent derivatization reagents for covalently labeling proteins. Fluorescein isothiocyanates (FITC) are the predominantly used fluorescein derivatives. But alternative derivatives offer significant advantages. Carboxyfluorescein succinimidyl esters react faster than FITC and yield conjugates with higher resistance against hydrolysis. An advantage of fluorescein dichlorotriazine (DTAF) is its direct reactivity with polysaccharides and other alcohols in aqueous solutions at pH greater than nine. 6-carboxy-4',5'-dichloro-2',7'-dimethoxyfluorescein (JOE) is very common as label for automated nucleic acid sequencing. The synthesis of these derivatives typically results in a mixture of isomers, which are almost indistinguishable in both wavelength and intensity, but may differ in the geometry of their binding to proteins. Certain applications may require the single-isomer preparations.

Product #	Description	Assay	Fluorescence	Add to Cart
07217	1-(O′-Methylfluoresceinyl)piperidine-4-carboxylic acid	≥95.0% (HPCE)		pricing

35845	2′,7′-Dichlorofluorescein diacetate	≥95% (HPLC)	λ_ex 504 nm; λ_em 524 nm in 0.1 M Tris pH 8.0 (esterase)	pricing

444839	4(5)-(Iodoacetamido)fluorescein			pricing

C7153	5(6)-Carboxyfluorescein Mixed isomers	~99% (HPLC)		pricing

C8166	5(6)-Carboxyfluorescein diacetate Mixed isomers	≥90% (HPLC)		pricing

21888	5(6)-Carboxyfluorescein diacetate N-succinimidyl ester	≥90% (HPLC)	λ_ex 492 nm; λ_em 517 nm in 0.1 M Tris pH 8.0 (esterase)	pricing

36565	5-(4,6-Dichloro-s-triazin-2-ylamino)fluorescein hydrochloride	≥99.0% (TLC)	λ_ex 492 nm; λ_em 514 nm in 0.1 M Tris pH 9.0	pricing

72755	5-(Bromomethyl)fluorescein	≥95% (sum of tautomers, GC)	λ_ex 492 nm; λ_em 515 nm in 0.1 M Tris pH 9.0	pricing

I9271	5-(Iodoacetamido)fluorescein	≥95% (HPLC)		pricing

D0531	5-([4,6-Dichlorotriazin-2-yl]amino)fluorescein hydrochloride	≥90% (HPLC)	λ_ex 495 nm; λ_em 516 nm	pricing

07980	5-Aminofluorescein	≥90% (HPLC)		pricing

87444	5-Carboxy-fluorescein diacetate N-succinimidyl ester	≥95.0% (HPLC)		pricing

86826	5-Carboxyfluorescein	≥95% (HPLC)	λ_ex 492 nm; λ_em 517 nm in 0.1 M Tris pH 8.0	pricing

92846	5-Carboxyfluorescein N-succinimidyl ester	≥90% (HPLC)	λ_ex 492 nm; λ_em 520 nm in 0.1 M Tris pH 8.0	pricing

D9908	6-([4,6-Dichlorotriazin-2-yl]amino)fluorescein hydrochloride	≥90% (HPLC)		pricing

C4109	6-Carboxy-4′,5′-dichloro-2′,7′-dimethoxyfluorescein N-hydroxysuccinimide ester			pricing

08951	6-Carboxy-fluorescein diacetate N-succinimidyl ester	≥90.0% (HPLC)	λ_ex 492 nm; λ_em 517 nm in 0.1 M Tris pH 8.0 (after cleavage by esterase)	pricing

C0662	6-Carboxyfluorescein	~97% (HPLC)		pricing

54115	6-Carboxyfluorescein	≥95% (HPLC)	λ_ex 492 nm; λ_em 517 nm in 0.1 M Tris pH 8.0	pricing

52352	6-Carboxyfluorescein N-hydroxysuccinimide ester	≥85% (HPLC) ≥90% (coupling to amines)	λ_ex 492 nm; λ_em 516 nm in 0.1 M Tris pH 8.0	pricing

46935	6-[Fluorescein-5(6)-carboxamido]hexanoic acid	≥90% (HPCE)	λ_ex 491 nm; λ_em 515 nm in 0.1 M Tris pH 9.0	pricing

46940	6-[Fluorescein-5(6)-carboxamido]hexanoic acid N-hydroxysuccinimide ester	≥75% (HPLC)	λ_ex 491 nm; λ_em 515 nm in 0.1 M Tris pH 9.0	pricing

E6003	Eosin Y disodium salt			pricing

E4382	Eosin Y disodium salt			pricing

32617	Eosin Y disodium salt			pricing

45240	Eosin Y disodium salt			pricing

318906	Eosin Y solution			pricing

F2456	Fluorescein (free acid)			pricing

F3651	Fluorescein 5(6)-isothiocyanate	~90% (HPLC)		pricing

46950	Fluorescein 5(6)-isothiocyanate	≥90% (HPLC)	λ_ex 492 nm; λ_em 518 nm in 0.1 M phosphate pH 8.0	pricing

46939	Fluorescein diacetate 5-maleimide	≥98% (HPCE)	λ_ex 492 nm; λ_em 530 nm in 0.1 M phosphate pH 7.0 (after derivatization with 2-mercaptoethanol and after cleavage by esterase)	pricing

36438	Fluorescein diacetate 6-isothiocyanate	≥90% (HPLC)	λ_ex 496 nm; λ_em 517 nm in 0.1 M Tris pH 8.0, esterase	pricing

F7250	Fluorescein isothiocyanate isomer I	≥90% (HPLC)	λ_ex 492 nm; λ_em 518 nm (green)	pricing

F4274	Fluorescein isothiocyanate isomer I	~98% (HPLC)	λ_ex 492 nm; λ_em 518 nm (green)	pricing

46951	Fluorescein isothiocyanate isomer I	≥97.5% (HPLC)	λ_ex 492 nm; λ_em 518 nm (green) λ_ex 492 nm; λ_em 518 nm in 0.1 M phosphate pH 8.0	pricing

46952	Fluorescein isothiocyanate isomer I	≥90% (HPLC)	λ_ex 492 nm; λ_em 518 nm (green) λ_ex 492 nm; λ_em 518 nm in 0.1 M phosphate pH 8.0	pricing

F2502	Fluorescein isothiocyanate isomer I	90%	λ_ex 492 nm; λ_em 518 nm (green)	pricing

46980	Fluorescein mercuric acetate	~90% (UV)		pricing

28803	Fluorescein sodium salt	98.5-100.5% (calc. on dry substance)		pricing

46970	Fluorescein sodium salt			pricing

F9551	Fluorescein-5-EX N-hydroxysuccinimide ester			pricing

88596	Fluorescein-O′-acetic acid	≥90% (HPCE)	λ_ex 455 nm; λ_em 514 nm in 0.1 M Tris pH 8.0	pricing

63869	Mercury dibromofluorescein disodium salt	≥85.0% (Hg)		pricing

07294	O′-(Carboxymethyl)fluoresceinamide	≥97.0% (HPCE)	λ_ex 458 nm; λ_em 520 nm in methanol	pricing

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