ICG Isothiocyanate

ICG Isothiocyanate is an isothiocyanate-functionalized near-infrared cyanine dye derived from indocyanine frameworks, designed for covalent fluorescent labeling of amine-containing biomolecules. Its electrophilic isothiocyanate group enables stable thiourea formation with primary amines, making it a common reagent for constructing fluorescent conjugates used in optical imaging workflows where deep-tissue or low-background NIR readout is advantageous.

1. Protein Conjugation

ICG Isothiocyanate is frequently used by protein engineering and chemical biology groups to prepare dye-labeled antibodies, enzymes, affinity reagents, and carrier proteins for fluorescence imaging and fluorescence-based binding studies. The isothiocyanate handle reacts with lysine residues and N-termini under standard bioconjugation conditions, yielding stable covalent conjugates that can be used to track biomolecule localization, quantify binding in plate-based assays, or generate fluorescent standards for imaging experiments.

2. Bioconjugated Imaging Probes

ICG Isothiocyanate supports the development of NIR fluorescent imaging reagents for molecular imaging research, including labeling of targeting ligands such as peptides and small proteins used in conjugate-based imaging constructs. Researchers use the reactive dye to install a near-infrared fluorophore onto targeting scaffolds and assemble imaging probes for optical readouts in microscopy and whole-sample fluorescence imaging setups, where NIR emission helps reduce background from autofluorescence.

3. Surface and Nanomaterial Labeling

ICG Isothiocyanate is used in biomaterials and materials chemistry workflows to fluorescently tag amine-functionalized surfaces and carriers, including polymer coatings, nanoparticles, and hydrogel matrices prepared with accessible primary amine groups. By covalently attaching the dye to amine-bearing materials, researchers can create stable NIR-labeled materials for tracking material distribution, monitoring coating integrity, and visualizing interactions between functionalized biomaterials and biological components in fluorescence imaging experiments.

4. Fluorescent Tracing Assays

ICG Isothiocyanate is commonly employed in fluorescence tracing and labeling experiments where covalent NIR labeling of biomolecules is required for reproducible signal tracking. In assay development contexts, the dye conjugates are used as fluorescent reporters to follow transport, uptake, or binding of labeled components in controlled laboratory studies, including quantitative fluorescence measurements in microplate readers and imaging-based readouts, leveraging the dye's near-infrared emission for lower interference from visible-range fluorophores.