N-(m-PEG9)-N'-(PEG5-acid)-Cy5 | CAS 2107273-26-5

N-(m-PEG9)-N'-(PEG5-acid)-Cy5 is a Cy5-based fluorescent dye conjugated to polyethylene glycol (PEG) chains, providing a more bioconjugation-friendly, water-soluble labeling handle for fluorescence imaging workflows. The Cy5 chromophore supports red-channel fluorescence detection, while the PEG spacer architecture helps reduce nonspecific interactions and improves performance in conjugate and surface-labeling contexts.

1. Antibody And Protein Labeling

N-(m-PEG9)-N'-(PEG5-acid)-Cy5 is commonly used in fluorescent labeling of antibodies, antibody fragments, and other proteins for microscopy and fluorescence-based binding assays. Researchers and assay developers use the PEGylated Cy5 scaffold to prepare conjugates that retain strong red fluorescence while often showing reduced aggregation and improved handling in aqueous buffers. The PEG spacers help maintain biomolecular accessibility, which is particularly useful when labeling targeting proteins intended for imaging, flow-based binding readouts, or fluorescent tracking of biomolecule interactions.

2. Cell Imaging Tracers

N-(m-PEG9)-N'-(PEG5-acid)-Cy5 is applied as a red fluorescent tracer in cellular imaging experiments where stable, water-compatible labeling reagents are required. In cell biology workflows, the PEGylated Cy5 dye is used to generate fluorescent conjugates for uptake studies, extracellular binding visualization, and wash-resistant staining formats compatible with standard fluorescence microscopy instrumentation. The dye's red emission is leveraged to minimize spectral overlap with common green fluorophores, supporting multicolor experimental design in imaging and imaging-guided assay development.

3. Biomaterial Surface Functionalization

N-(m-PEG9)-N'-(PEG5-acid)-Cy5 is frequently incorporated into biomaterial and surface functionalization strategies to create fluorescently trackable materials for materials science and chemical biology research. Investigators use the PEGylated Cy5 scaffold to label hydrophilic surfaces, coatings, and polymer constructs, enabling visualization of material distribution, adhesion, and stability under experimental conditions. The PEG architecture helps maintain dye presentation away from the surface, supporting more consistent fluorescence readouts in microscopy and fluorescence imaging of labeled scaffolds, films, or engineered interfaces.

4. Fluorescent Conjugate Standards

N-(m-PEG9)-N'-(PEG5-acid)-Cy5 is also used as a reference fluorophore in assay development and method optimization where reliable red-channel fluorescence is needed. Researchers prepare labeled conjugates or dye-containing controls to calibrate imaging workflows, validate labeling consistency across batches, and support routine quality checks in fluorescence microscopy and fluorescence-based quantification experiments. The PEGylated format provides convenient aqueous handling for preparing reproducible standards used in experimental controls and comparative studies of fluorescent labeling performance.