Cy5-PEG5-amine HCl salt

Cy5-PEG5-amine HCl salt is a Cy5-based fluorescent labeling reagent featuring a terminal primary amine for straightforward conjugation to amine-reactive handles on biomolecules, polymers, and surfaces. The PEG spacer helps reduce steric crowding and supports more uniform dye presentation in conjugates used for fluorescence imaging and quantitative fluorescence workflows. Its red-emitting Cy5 chromophore is commonly selected for multicolor labeling strategies where compatibility with standard far-red detection channels is required.

1. Protein And Peptide Labeling

Cy5-PEG5-amine HCl salt is used by protein and peptide labeling teams to prepare fluorescent conjugates for fluorescence microscopy and fluorescence-based binding studies. Researchers typically incorporate the dye into antibody fragments, enzymes, affinity ligands, and peptide probes by coupling the terminal amine to activated carboxyl groups or by transferring the dye into downstream conjugation schemes that require a defined dye-to-biomolecule ratio. The PEG5 linker improves dye spacing relative to densely functional biomolecules, supporting consistent labeling behavior in imaging experiments and reducing aggregation-prone dye presentation.

2. Biomolecule Conjugate Building

Cy5-PEG5-amine HCl salt serves as a practical fluorescent building block for constructing labeled biomolecule conjugates used in chemical biology and assay development. Teams developing fluorescent tracers, affinity reagents, and labeling standards use the amine functionality to attach Cy5 to carrier proteins, nucleic-acid-associated scaffolds, or polymer backbones that present reactive coupling sites. This workflow is particularly common when a far-red dye label is required for visualization and quantification while maintaining a flexible PEG spacer between the fluorophore and the conjugation point.

3. Surface and Material Functionalization

Cy5-PEG5-amine HCl salt is applied in biomaterials and surface engineering workflows to generate fluorescently tagged surfaces and coatings for imaging and material characterization. Researchers use the terminal amine to immobilize Cy5-containing linkers onto activated substrates, enabling mapping of surface coverage and tracking of material-associated processes in microscopy readouts. The PEG spacer supports more controlled dye presentation on surfaces, which helps maintain reliable fluorescence signals in labeling studies where dye crowding can otherwise complicate interpretation.

4. Fluorescence Imaging Tracers

Cy5-PEG5-amine HCl salt is frequently used to create fluorescent imaging tracers for cellular and molecular imaging experiments in which red/far-red fluorescence provides separation from green-channel labels. Imaging teams prepare conjugates for tracking biomolecule localization, following transport of labeled constructs, and visualizing binding events in fluorescence microscopy workflows. The combination of a Cy5 fluorophore and a PEG5 linker supports tracer designs where the dye remains accessible to the optical system while remaining tethered to the targeting or carrier component through a defined functional handle.