Product number: AF-0106

6-Carboxyfluorescein NHS ester, single isomer (6-FAM-SE)

Amine-reactive fluorescein dye marker for fluorescence labeling, especially for labeling of biomolecules (Abs: 497 nm, Em: 519 nm).

This item is not on stock and has to be re-ordered.

CAS-Number:	92557-81-8
Molecular Weight:	473,9
Empirical Formula:	C₂₅H₁₅NO₉
Absorption [nm]:	492 ± 3
Emission [nm]:	514 ± 3
ε [M-1 cm-1]:	>81 000
Excitation [nm]:	498
Buffer System for Fluorescence Readings:	PBS, pH 7.4
Solubility:	Acetonitril, DMF, DMSO
Appearance (colour):	orange
Appearance (form):	solid (powder)
Storage:	- 20 °C. Keep dry! Keep away from light, especially in solution!
Name:	2-(6-Hydroxy-3-oxo-3H-xanthen-9-yl)-terephthalic acid 4-(2,5-dioxo-pyrrolidin-1-yl) ester
Trade name:	6-Carboxyfluorescein-NHS-ester; 6-FAM-SE; 6-carboxyfluorescein succinimidyl ester, single isomers
Reactive Moiety:	NHS ester, reacts with 1° amines to form a stable amide linkage

This single isomer amine-reactive derivatization reagent may be used for covalent labeling of proteins and alkylamino modified nucleic acids.

Fluorescein has an excitation maximum that closely matches the 488 nm spectral line of the argon-ion laser, making it the predominant fluorophore for confocal laser scanning microscopy and flow cytometry applications.

It has a relatively high absorptivity, excellent fluorescence quantum yield, and good water solubility. Importantly, protein-fluorescein conjugates are not inordinately susceptible to precipitation.