Cyanine7.5 NHS ester

Cyanine7.5 NHS ester is a reactive cyanine dye designed for amine-selective fluorescent labeling via its N-hydroxysuccinimide (NHS) ester group. Upon conjugation to primary amines on proteins, peptides, and other biomolecules, it provides a far-red fluorescence signal that is widely used for sensitive imaging and fluorescence-based assays. Its strong spectral separation from common visible fluorophores makes it a practical choice for multicolor workflows and fluorescence readouts in microscopy and analytical platforms.

1. Protein Fluorescent Labeling

Cyanine7.5 NHS ester is routinely used to generate far-red fluorescent protein conjugates for binding studies, imaging reagents, and fluorescence assay development. Researchers label antibodies, antibody fragments, enzymes, serum proteins, and purified protein standards to track biomolecular localization and interactions in solution or on surfaces. The NHS ester reactivity enables straightforward attachment to lysine residues and N-terminal amines, supporting downstream use in fluorescence microscopy, plate-based fluorescence assays, and imaging readouts where far-red emission helps reduce spectral overlap with green and red channels.

2. Antibody Conjugates For Imaging

Cyanine7.5 NHS ester supports the construction of fluorescent antibody conjugates for immunofluorescence workflows and targeted imaging reagent development. By attaching the dye to antibody primary amines, teams create far-red immunolabeling tools for microscopy experiments that require robust signal in the red/far-red range and compatibility with common filter sets used for Cy7.5-like emission. This labeling strategy is frequently applied when multicolor panels are needed, such as combining antibody staining with additional fluorophores while maintaining clear channel separation for quantitative imaging.

3. Peptide And Biomolecule Marking

Cyanine7.5 NHS ester is used to fluorescently tag peptides and other amine-containing biomolecules used as probes, tracers, or assay components. In chemical biology and biomaterials research, labeled peptides can serve as binding ligands, uptake tracers, or reference standards for fluorescence-based characterization of interactions with receptors, surfaces, or polymer matrices. The dye's NHS ester functionality enables conjugation to peptides bearing accessible primary amines, facilitating preparation of labeled biomolecules for fluorescence imaging, normalization controls, and comparative studies across experimental conditions.

4. Fluorescent Standards And Tracers

Cyanine7.5 NHS ester is also leveraged to prepare fluorescent standards and labeling reagents for quantitative fluorescence workflows. Laboratories use dye-labeled small biomolecules and protein conjugates as calibration references for far-red channel intensity, enabling consistent normalization across imaging sessions and instrument runs. In tracer-style experiments, far-red labeled conjugates help visualize transport, distribution, or retention in materials and assay formats where minimizing interference from shorter-wavelength fluorophores is advantageous.