N-Methyl-N'-(hydroxy-PEG2)-Cy5 | CAS 2107273-22-1

N-Methyl-N'-(hydroxy-PEG2)-Cy5 is a Cy5-based fluorescent dye bearing a terminal hydroxy-PEG2 substituent, designed to improve aqueous handling and provide a convenient handle for downstream conjugation or formulation. In fluorescence workflows, Cy5 emission supports red-channel imaging and labeling strategies where bright far-red readouts and flexible dye spacing are beneficial for biomolecule tracking and assay development.

1. Fluorescent Bioconjugation Labeling

N-Methyl-N'-(hydroxy-PEG2)-Cy5 is used to generate fluorescently labeled biomolecules for microscopy and quantitative fluorescence assays, particularly when a PEG spacer helps reduce steric interference between the dye and the labeled target. Researchers commonly incorporate this Cy5 derivative into labeling pipelines for proteins, peptides, and other macromolecules where far-red fluorescence is tracked to monitor binding, localization, or distribution in complex biological matrices. The PEG2-bearing hydroxy functionality supports practical conjugate construction workflows that require a dye-compatible attachment point rather than relying on direct dye adsorption.

2. Fluorescence Microscopy Tracing

N-Methyl-N'-(hydroxy-PEG2)-Cy5 is frequently selected for cellular and biomaterials microscopy experiments that benefit from Cy5 far-red emission, such as multicolor imaging panels where spectral separation from green and orange channels is required. Investigators use Cy5 labeling to visualize labeled proteins, extracellular components, or surface-associated probes in fixed-sample imaging and fluorescence localization studies. The PEG2 substituent helps maintain dye performance in aqueous staining buffers and can support more reproducible labeling when dye crowding would otherwise influence signal appearance.

3. Flow Cytometry Dye Conjugates

N-Methyl-N'-(hydroxy-PEG2)-Cy5 is applied in flow cytometry workflows through the preparation of Cy5-conjugated reagents used to quantify fluorescence intensity on labeled cell populations. In research settings, this dye is incorporated into conjugate formats for tracking biomolecule binding events, monitoring reagent uptake, or reporting on surface-associated labeling readouts in red fluorescence channels. The PEG2-containing structure supports consistent dye presentation in conjugates, which is important when comparing staining conditions across experiments and maintaining reliable fluorescence behavior during sample processing.

4. Imaging Probe and Assay Development

N-Methyl-N'-(hydroxy-PEG2)-Cy5 supports fluorescence probe development for assay formats that rely on far-red signal readout, including endpoint fluorescence measurements and imaging-based screening of labeled constructs. Chemical biology teams use Cy5 labeling to build detection reagents for tracking reaction products, monitoring biomolecular assembly, or reporting on probe distribution within assay wells or imaging chambers. The hydroxy-PEG2 motif provides a practical platform for integrating the dye into larger probe architectures, including conjugate libraries where dye spacing and aqueous compatibility influence reproducibility.