ATTO 565 NHS ester | CAS 1443553-12-5

ATTO 565 NHS ester is a reactive ATTO 565 fluorophore formulated as an N-hydroxysuccinimide (NHS) ester for efficient covalent labeling of primary amines. Its bright red-orange fluorescence supports fluorescence microscopy and fluorescence-based quantification workflows where stable dye conjugates are needed. The NHS-ester reactivity makes it widely used for preparing labeled proteins, antibodies, and other amine-containing biomolecules for imaging and assay development.

1. Protein And Antibody Labeling

ATTO 565 NHS ester is frequently used by protein engineering and antibody labeling teams to generate fluorescently tagged immunoreagents for cellular imaging and binding studies. Because NHS esters react with lysine side-chain amines and N-terminal amines, the dye conjugates can be prepared for microscopy experiments, flow cytometry sample staining, and fluorescence readouts in binding assays. Researchers often select ATTO 565 labeling when they need a red-emitting dye compatible with common fluorescence microscope filter sets and multi-color experimental designs that include green/blue channels.

2. Fluorescence Microscopy Staining

ATTO 565 NHS ester supports fluorescence microscopy workflows that require covalent, wash-resistant labeling of amine-rich targets such as fixed-cell protein markers, extracellular matrix components, or labeled secondary reagents used for immunostaining strategies. Imaging groups use the dye-conjugated biomolecules to visualize spatial distribution and colocalization patterns in cell biology studies, including experiments where consistent signal retention after washing is important. The dye's red-orange emission is also commonly leveraged to reduce spectral overlap with shorter-wavelength fluorophores in multi-channel microscopy.

3. Fluorescent Bioassay Reagent Development

ATTO 565 NHS ester is used in assay development to prepare fluorescent conjugates for plate-based fluorescence measurements and reagent standardization. In biochemical screening and binding assays, amine-reactive labeling enables incorporation of the fluorophore into proteins, peptides, or other amine-containing assay components used as fluorescent reporters. Assay developers often rely on covalent dye conjugation to minimize dye loss during incubation and washing steps, improving the robustness of fluorescence signals in routine lab workflows.

4. Flow Cytometry Conjugate Preparation

ATTO 565 NHS ester is a common choice for preparing flow cytometry staining reagents where red fluorescence is collected alongside other channels. Cytometry users label amine-containing antibodies or proteins to enable quantification of binding to cell-surface or intracellular targets after appropriate fixation/permeabilization workflows. The covalent NHS-ester chemistry supports consistent labeling across samples, which is valuable for comparative experiments, panel development, and fluorescence-based gating strategies in multi-color cytometry experiments.