Name: iFluor® 440 succinimidyl ester
Brand: AAT Bioquest
SKU: 1041
Availability: InStock

iFluor® 440 succinimidyl ester

iFluor® 440 Succinimidyl Ester is an amine-reactive fluorescent dye for covalent labeling of proteins, particularly antibodies, in fluorescence-based research applications.

Amine-Reactive Functionality: NHS ester selectively reacts with primary amines, including lysine residues.
Spectral Properties: Excitation at 434 nm and emission at 480 nm.
Fluorescence Performance: Bright, photostable fluorescence with minimal quenching.
Enhanced Brightness: Manufacturer-reported higher fluorescence intensity than comparable DEAC and SpectrumAqua conjugates.
Applications: Suitable for fluorescent conjugation of antibodies and other amine-containing proteins.

Protocol

Catalog	Size	Price
1041	1 mg	Price
71041	100 ug	Price
71519	5 mg	Price
71569	10 mg	Price

Overview

AAT Bioquest's iFluor® dyes are optimized for labeling proteins, particularly antibodies. These dyes are bright, photostable, and have minimal quenching on proteins. They can be well excited by the major laser lines of fluorescence instruments (e.g., 350, 405, 488, 555, and 633 nm). iFluor® 440 dyes are designed to be a superior replacement for DEAC dye that has extremely poor water solubility. iFluor® 440 SE is reasonably stable and shows good reactivity and selectivity with protein amino groups. Under the same conditions, iFluor® 440 dye conjugates are significantly brighter than the corresponding bioconjugates of DEAC or other spectrally similar dyes (such as SpectrumAqua), making the iFluor® 440 conjugates much more sensitive.

Calculators

Common stock solution preparation

Table 1. Volume of DMSO needed to reconstitute specific mass of iFluor® 440 succinimidyl ester to given concentration. Note that volume is only for preparing stock solution. Refer to sample experimental protocol for appropriate experimental/physiological buffers.

	0.1 mg	0.5 mg	1 mg	5 mg	10 mg
1 mM	144.336 µL	721.678 µL	1.443 mL	7.217 mL	14.434 mL
5 mM	28.867 µL	144.336 µL	288.671 µL	1.443 mL	2.887 mL
10 mM	14.434 µL	72.168 µL	144.336 µL	721.678 µL	1.443 mL

Molarity calculator

Enter any two values (mass, volume, concentration) to calculate the third.

Mass (Calculate)		Molecular weight		Volume (Calculate)		Concentration (Calculate)		Moles
mg	÷	692.83 g/mol	=	mL	x	mM	=	mmol

References

View all 12 references: Citation Explorer

7-(Diethylamino)coumarin-3-carboxylic acid as derivatization reagent for 405 nm laser-induced fluorescence detection: A case study for the analysis of sulfonamides by capillary electrophoresis.

Authors:

Wu, Chengxin and Sun, Yuanyuan and Wang, Yuanhang and Duan, Wenzhen and Hu, Jiangyue and Zhou, Lei and Pu, Qiaosheng

Journal:

Talanta (2019): 16-22

Design, synthesis and perception of fluorescently labeled isoprenoid cytokinins.

Authors:

Kubiasová, Karolina and Mik, Václav and Nisler, Jaroslav and Hönig, Martin and Husičková, Alexandra and Spíchal, Lukáš and Pěkná, Zuzana and Šamajová, Olga and Doležal, Karel and Plíhal, Ondřej and Benková, Eva and Strnad, Miroslav and Plíhalová, Lucie

Journal:

Phytochemistry (2018): 1-11

Intracellular Uncaging of cGMP with Blue Light.

Authors:

Agarwal, Hitesh K and Zhai, Shenyu and Surmeier, D James and Ellis-Davies, Graham C R

Journal:

ACS chemical neuroscience (2017): 2139-2144

Wavelength-selective one- and two-photon uncaging of GABA.

Authors:

Amatrudo, Joseph M and Olson, Jeremy P and Lur, G and Chiu, Chiayu Q and Higley, Michael J and Ellis-Davies, Graham C R

Journal:

ACS chemical neuroscience (2014): 64-70

A water soluble fluorescent polymer as a dual colour sensor for temperature and a specific protein.

Authors:

Inal, Sahika and Kölsch, Jonas D and Sellrie, Frank and Schenk, Jörg A and Wischerhoff, Erik and Laschewsky, André and Neher, Dieter

Journal:

Journal of materials chemistry. B (2013): 6373-6381

Physical properties

Molecular weight	692.83
Solvent	DMSO

Spectral properties

Absorbance (nm)	430
Correction factor (260 nm)	0.352
Correction factor (280 nm)	0.229
Extinction coefficient (cm ^-1 M ^-1)	40000 ¹
Excitation (nm)	434
Emission (nm)	480
Quantum yield	0.67 ¹

Usage and storage

Intended use	Research Use Only (RUO)
Storage	Freeze (< -15 °C); Minimize light exposure

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Page updated on October 24, 2026