AATOM™ 425 NHS ester

AATOM™ 425 NHS ester is an amine‑reactive, blue fluorescent dye with an excitation/emission of 438/484 nm that is used for FACS and FISH applications.

Rapid Amide‑Bond Formation: Selective reaction with primary amines on peptides, amine‑modified oligonucleotides, and aminosilane-coated surfaces
High Quantum Yield & Photostability: Produces bright, durable fluorescence
Enhanced Signal Separation: Reduced background through large Stokes shift

The chemical structure of AATOM™ 425 NHS ester.

Protocol

SDS

Catalog	Size	Price	Quantity
70211	1 mg	Price

Overview

AATOM™ 425 is a coumarin-based fluorescent dye characterized by its high fluorescence quantum yield, large Stokes shift, excellent photostability, and low molecular weight. It exhibits moderate hydrophilicity and is optimally excited in the 405-455 nm wavelength range. These properties make AATOM™ 425 particularly suitable for applications in single-molecule detection and high-resolution microscopy techniques, including PALM, dSTORM, and STED microscopy. Additionally, AATOM™ 425 is well-suited for use in flow cytometry (FACS), fluorescence in situ hybridization (FISH), and various other biological assays.

NHS esters react selectively and efficiently with primary amines (such as the side chains of lysine residues or aminosilane-coated surfaces) at pH 7-9, forming stable covalent amide bonds. This property makes AATOM™ 425 NHS ester an excellent choice for labeling peptides and amine-modified oligonucleotides. For labeling antibodies and other proteins, we highly recommend our iFluor® dyes that are highly water soluble and are optimized for labeling proteins. This product is manufactured by AAT Bioquest and is not affiliated with ATTO-TEC GmbH.

Calculators

Common stock solution preparation

Table 1. Volume of DMSO needed to reconstitute specific mass of AATOM™ 425 NHS 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	200.59 µL	1.003 mL	2.006 mL	10.029 mL	20.059 mL
5 mM	40.118 µL	200.59 µL	401.179 µL	2.006 mL	4.012 mL
10 mM	20.059 µL	100.295 µL	200.59 µL	1.003 mL	2.006 mL

Molarity calculator

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

Mass (Calculate)		Molecular weight		Volume (Calculate)		Concentration (Calculate)		Moles
mg	÷	498.53 g/mol	=	mL	x	mM	=	mmol

References

View all 4 references: Citation Explorer

Ratiometric Fluorescent Biosensor Based on Self-Assembled Fluorescent Gold Nanoparticles and Duplex-Specific Nuclease-Assisted Signal Amplification for Sensitive Detection of Exosomal miRNA.

Authors:

Sun, Zhiwei and Li, Juan and Yang, Yufei and Tong, Yao and Li, Hui and Wang, Chuanxin and Du, Lutao and Jiang, Yanyan

Journal:

Bioconjugate chemistry (2022): 1698-1706

Ratiometric Fluorescence Detection of Colorectal Cancer-Associated Exosomal miR-92a-3p with DSN-Assisted Signal Amplification by a MWCNTs@Au NCs Nanoplatform.

Authors:

Sun, Zhiwei and Li, Juan and Tong, Yao and Zhao, Li and Zhou, Xiaoyu and Li, Hui and Wang, Chuanxin and Du, Lutao and Jiang, Yanyan

Journal:

Biosensors (2022)

Avidin/Biotin Bioinspired Platform for Dual In Vivo 18F-PET/NIRF Molecular Imaging.

Authors:

Damont, Annelaure and Boisgard, Raphael and Dollé, Frédéric and Hollocou, Morgane and Kuhnast, Bertrand

Journal:

Bioconjugate chemistry (2017): 2524-2529

Fluorescence of dyes in solutions with high absorbance. Inner filter effect correction.

Authors:

Fonin, Alexander V and Sulatskaya, Anna I and Kuznetsova, Irina M and Turoverov, Konstantin K

Journal:

PloS one (2014): e103878

Physical properties

Molecular weight	498.53
Solvent	DMSO

Spectral properties

Correction factor (260 nm)	0.19
Correction factor (280 nm)	0.17
Extinction coefficient (cm ^-1 M ^-1)	45000
Excitation (nm)	438
Emission (nm)	484
Quantum yield	0.90

Storage, safety and handling

H-phrase	H303, H313, H333
Hazard symbol	XN
Intended use	Research Use Only (RUO)
R-phrase	R20, R21, R22
Storage	Freeze (< -15 °C); Minimize light exposure
UNSPSC	12352200

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Page updated on March 14, 2026