N-methyl-N'-methyl-O-(m-PEG4)-O'-(propargyl-PEG4)-Cy5 | CAS 2107273-50-5

N-methyl-N'-methyl-O-(m-PEG4)-O'-(propargyl-PEG4)-Cy5 is a PEGylated Cy5-based fluorescent labeling reagent bearing a terminal propargyl group for copper-free click conjugation workflows and a Cy5 chromophore for far-red fluorescence readouts. Its PEG spacers are designed to improve conjugate solubility and reduce nonspecific interactions during labeling of biomolecules, polymers, and surfaces. This combination makes the reagent useful for constructing fluorescent bioconjugates, imaging probes, and labeled materials where stable far-red tracking is required.

1. Biomolecule Click Labeling

N-methyl-N'-methyl-O-(m-PEG4)-O'-(propargyl-PEG4)-Cy5 is commonly used to fluorescently tag azide-functional biomolecules produced in chemical biology workflows, including peptides, proteins, and oligonucleotide conjugates that carry azide handles. Researchers use the propargyl functionality to attach the Cy5 fluorophore to biomolecular targets while the PEG linkers help maintain aqueous compatibility and reduce aggregation during labeling and purification. The far-red Cy5 emission is particularly favored for multiplex-friendly imaging and for workflows that benefit from reduced background autofluorescence compared with shorter-wavelength dyes.

2. Fluorescence Imaging Tracers

N-methyl-N'-methyl-O-(m-PEG4)-O'-(propargyl-PEG4)-Cy5 supports fluorescence microscopy and related imaging studies where stable far-red contrast is needed to track labeled components in complex samples. In practice, users incorporate the reagent into fluorescent tracers for monitoring biomaterial-associated distributions, labeled macromolecules in cellular or extracellular environments, and spatial localization of click-assembled conjugates. The PEGylated structure helps the resulting conjugates remain dispersible in aqueous buffers, which is helpful for consistent staining and imaging across time-course experiments.

3. Surface And Polymer Functionalization

N-methyl-N'-methyl-O-(m-PEG4)-O'-(propargyl-PEG4)-Cy5 is frequently employed to generate Cy5-labeled functional materials by click attachment to azide-bearing surfaces, coatings, or polymer scaffolds. Material scientists and biomaterials researchers use the propargyl group to incorporate Cy5 into hydrophilic, PEG-spaced architectures that can be imaged by standard far-red fluorescence instrumentation. This approach is used to create fluorescently addressable materials for studying binding, transport, and spatial organization on engineered substrates, hydrogels, or polymer films.

4. Fluorescent Probe Construction

N-methyl-N'-methyl-O-(m-PEG4)-O'-(propargyl-PEG4)-Cy5 is used as a building block for assembling fluorescent probes and detection reagents where a Cy5 reporter is required at a defined position within a conjugate. Probe developers incorporate the reagent into click-assembled constructs to generate labeled affinity reagents, multicomponent imaging probes, or assay-compatible conjugates that can be tracked optically. The PEG spacers help preserve probe dispersibility and reduce nonspecific adsorption, supporting cleaner fluorescence readouts in heterogeneous assay formats.