Atto 565 NHS ester

BioReagent, suitable for fluorescence, ≥70.0% (coupling to amines)

Empirical Formula (Hill Notation):
Molecular Weight:
MDL number:

Quality Level

product line



≥70.0% (coupling to amines)




λex 565 nm; λem 590 nm in 0.1 M phosphate pH 7.0


suitable for fluorescence

detection method


storage temp.


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General description

Atto 565 NHS ester is a commonly used amine-reactive reagent, provided by ATTO-TEC. It is widely used in protein labeling and readily reacts with compounds containing amino groups, forming a chemically stable amide bond between the dye, e.g., a protein. The optimum pH-range for NHS-ester coupling is pH 8.0 – 9.0. At this pH amino groups of proteins, i.e., the ε-amino groups of lysines are unprotonated to a degree sufficiently high for fast coupling.

Features and Benefits

  • Strong absorption
  • High fluorescence quantum yield
  • High thermal and photo-stability

Other Notes

Fluorescence of bioconjugates; employed in fluorescence resonance energy transfer, FRET, experiments.

Legal Information

This product is for Research use only. In case of intended commercialization, please contact the IP-holder (ATTO-TEC GmbH, Germany) for licensing.

Personal Protective Equipment

dust mask type N95 (US),Eyeshields,Gloves


NONH for all modes of transport

WGK Germany


Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis

Certificate of Origin

Benjamin Zoller et al.
Cell, 175(3), 835-847 (2018-10-20)
How transcriptional bursting relates to gene regulation is a central question that has persisted for more than a decade. Here, we measure nascent transcriptional activity in early Drosophila embryos and characterize the variability in absolute activity levels across expression boundaries....
Elizabeth A Jares-Erijman et al.
Nature biotechnology, 21(11), 1387-1395 (2003-11-05)
Förster (or Fluorescence) Resonance Energy Transfer (FRET) is unique in generating fluorescence signals sensitive to molecular conformation, association, and separation in the 1-10 nm range. We introduce a revised photophysical framework for the phenomenon and provide a systematic catalog of...
Michael Cooper et al.
Journal of fluorescence, 14(2), 145-150 (2004-12-24)
The spectral properties of a rigidified trimethine cyanine dye, Cy3B have been characterised. This probe has excellent fluorescent properties, good water solubility and can be bioconjugated. The emission properties of this fluorophore have also been investigated upon conjugation to an...
Rachael Bakker et al.
eLife, 9 (2020-06-23)
Morphogen signaling contributes to the patterned spatiotemporal expression of genes during development. One mode of regulation of signaling-responsive genes is at the level of transcription. Single-cell quantitative studies of transcription have revealed that transcription occurs intermittently, in bursts. Although the...
Matthew G Niepielko et al.
Current biology : CB, 28(12), 1872-1881 (2018-06-05)
The formation of ribonucleoprotein assemblies called germ granules is a conserved feature of germline development. In Drosophila, germ granules form at the posterior of the oocyte in a specialized cytoplasm called the germ plasm, which specifies germline fate during embryogenesis. mRNAs...
Fluorescent Labeling of Peptides
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