Quasar705 NHS Ester

Quasar705 NHS Ester is an NHS-ester activated dye designed for efficient covalent attachment to primary amines on proteins, peptides, and other amine-containing biomolecules. As a far-red fluorescent labeling reagent, it is commonly used to generate stable fluorescent conjugates for fluorescence imaging and assay development, where its emission in the 700 nm region supports low-background detection with standard far-red channels. The activated NHS group enables straightforward incorporation into bioconjugates used in labeling workflows, including antibody conjugation and probe construction.

1. Antibody And Protein Labeling

Quasar705 NHS Ester is frequently used by immunochemistry and molecular biology teams to prepare far-red fluorescent antibody conjugates for binding studies and imaging workflows. Researchers label purified antibodies, antibody fragments, and protein reagents to enable fluorescence microscopy readouts of target binding on cells, tissue sections, or immobilized biomolecular targets. Because the dye is supplied as an NHS ester, it reacts with lysine residues and N-termini under standard bioconjugation conditions, producing covalently linked fluorescent conjugates that are well suited for downstream assay formats requiring stable labeling.

2. Fluorescent Probe Construction

Quasar705 NHS Ester is used in fluorescent probe development to generate labeled affinity reagents and detection probes that require far-red emission for multiplex-friendly imaging. In chemical biology and biomolecular detection workflows, the dye is commonly incorporated into oligonucleotide-associated proteins, peptide probes, or other amine-bearing recognition elements to create modular fluorescent reporters. Far-red labeling with Quasar705 NHS Ester supports signal readout in fluorescence microscopy and plate-based fluorescence assays, where spectral separation from green and orange channels helps reduce background from autofluorescence and common assay components.

3. Flow Cytometry Dye Conjugates

Quasar705 NHS Ester is applied to prepare far-red flow cytometry reagents by covalently labeling amine-containing proteins used as staining reagents. Flow cytometry users incorporate the dye into antibodies or other targeting proteins to track specific binding events on cells with fluorescence detection in the far-red range. Covalent NHS-ester labeling helps maintain reporter retention during washing steps, supporting consistent staining and enabling researchers to include Quasar705-based channels in multicolor panels where emission near the 700 nm region provides practical spectral spacing.

4. Biomaterial Surface Functionalization

Quasar705 NHS Ester is also used in biomaterials and surface engineering workflows to introduce far-red fluorescent tags onto amine-functionalized materials. Researchers label amine-containing coatings, polymer surfaces, or protein-functionalized substrates to enable fluorescence-based visualization of surface coverage, immobilization efficiency, and spatial distribution in microscopy studies. This labeling approach supports materials characterization and assay development where fluorescent surface markers are used to track immobilized biomolecules during incubation, washing, and experimental handling.