IRDye® QC-1 NHS Ester | CAS 918324-42-2

IRDye® QC-1 NHS Ester is an IRDye-based N-hydroxysuccinimide (NHS) ester labeling reagent designed for efficient conjugation to primary amines on proteins, peptides, and antibody fragments. Its near-infrared fluorescence enables low-background imaging workflows where reduced tissue autofluorescence and convenient optical filtering are advantageous. In bioconjugation and fluorescent probe development, the NHS ester format supports rapid attachment to carrier biomolecules and affinity reagents used in microscopy, imaging, and fluorescence-based assay development.

1. Antibody And Protein Labeling

IRDye® QC-1 NHS Ester is used by antibody and protein engineering groups to generate near-infrared fluorescent conjugates for immunoassays, binding studies, and imaging-based characterization. Researchers typically label lysine-rich proteins, Fc-containing fragments, and enzyme conjugates to create stable fluorescent reagents for workflow development in fluorescence microscopy, plate-based readouts, and optical imaging setups that accept NIR excitation/emission. The NHS ester reactivity toward primary amines makes it practical for preparing dye-labeled secondary reagents, tracer proteins, and control conjugates for assay optimization.

2. Fluorescent Imaging Tracers

IRDye® QC-1 NHS Ester supports the construction of fluorescent imaging tracers used in molecular imaging reagent development and fluorescence-guided localization experiments. In these workflows, dye-labeled biomolecules are prepared to track distribution, binding, and wash behavior under experimental conditions relevant to imaging instrumentation. Common users include chemical biology and materials labs preparing labeled affinity binders, fluorescently tagged biomolecular components, and multi-component imaging reagents where NIR readout helps reduce interference from visible-range fluorophores.

3. Bioconjugated Assay Reagents

IRDye® QC-1 NHS Ester is applied to develop fluorescence-based assay reagents that rely on stable covalent dye attachment to biomolecular partners. Assay developers use NHS-ester labeling to prepare fluorescently tagged proteins for homogeneous or wash-based formats, including binding assays and fluorescence readouts where consistent labeling chemistry improves reagent reproducibility. The resulting IRDye conjugates are also used as reference standards and calibration materials in fluorescence assay development, helping teams validate optical settings and conjugate handling procedures during method development.

4. Surface And Biomaterial Functionalization

IRDye® QC-1 NHS Ester is used in biomaterials science to introduce near-infrared fluorescence onto amine-bearing surfaces and matrices for imaging and characterization of functional materials. Researchers functionalize amine-containing polymers, coatings, and protein-modified scaffolds to create fluorescently addressable materials for studying adsorption, surface coverage, and spatial distribution under microscopy or optical imaging. This application is particularly relevant when fluorescent labeling must be covalently installed on a biomolecule layer that presents accessible primary amines for NHS ester coupling.