Cyanine7 dicarboxylic acid

Cyanine7 dicarboxylic acid is a near-infrared cyanine dye featuring two carboxylic acid groups that support water-compatible handling and straightforward conjugation to biomolecules and materials. Its long-wavelength emission is commonly leveraged for reduced background in fluorescence imaging workflows, including microscopy-based localization and fluorescence readouts in assay development. The dye's anionic functionality also helps with formulation stability for labeling reagents used in research and analytical instrumentation.

1. Fluorescent Bioconjugate Labeling

Cyanine7 dicarboxylic acid is frequently used as a fluorescent label for proteins, peptides, and other targeting ligands in bioconjugation workflows where near-infrared imaging is preferred over visible dyes. Researchers incorporate the dye into antibody conjugates, affinity reagents, and ligand-carrier constructs to enable tracking of binding, distribution, and conjugate integrity during assay development and imaging studies. The carboxylic acid functionality supports common coupling strategies to introduce the dye onto amine- or hydroxyl-containing biomolecules, producing fluorescent conjugates that are routinely evaluated by fluorescence spectroscopy and gel-based or instrument-based readouts.

2. Fluorescence Microscopy Imaging

Cyanine7 dicarboxylic acid supports fluorescence microscopy applications that benefit from near-infrared detection, such as imaging labeled biomolecules in fixed samples and tracking fluorescent conjugates in multi-component preparations. Imaging teams use Cyanine7-labeled probes to visualize spatial localization in cell-associated or extracellular contexts where spectral separation from autofluorescence improves interpretability. The dye's NIR emission also makes it a practical choice for microscopy setups equipped with appropriate excitation/emission filters or laser lines, enabling consistent visualization across time-course experiments and comparative labeling conditions.

3. Flow Cytometry Fluorescent Labeling

Cyanine7 dicarboxylic acid is used to generate flow cytometry-compatible fluorescent conjugates for analyzing labeled biomolecules on cells or in heterogeneous mixtures. Flow cytometry users typically prepare Cyanine7-tagged antibodies, streptavidin/affinity reagents, or other fluorescent labeling constructs to quantify binding signals and compare populations under standardized staining conditions. The near-infrared spectral region helps reduce interference from common cellular autofluorescence, supporting cleaner gating and panel design when multiplexing with fluorophores that have different excitation/emission characteristics.

4. Nucleic Acid and Probe Conjugates

Cyanine7 dicarboxylic acid is also applied in the development of fluorescence-based nucleic acid reagents, where near-infrared readout can be advantageous for monitoring hybridization or tracking labeled oligonucleotides in analytical workflows. Researchers conjugate the dye to oligonucleotides or incorporate it into labeled probe constructs used for fluorescence detection in nucleic acid analysis formats. In these applications, the dye's carboxylic acid functionality enables coupling into probe synthesis and post-labeling workflows, supporting robust fluorescence readout on plate readers and fluorescence imaging systems configured for NIR detection.