Alexa Fluor488 NHS | CAS 1374019-99-4

Alexa Fluor488 NHS is an amine-reactive N-hydroxysuccinimide ester designed for fluorescent labeling of proteins, peptides, and other primary-amine-containing biomolecules. The dye's green emission is widely used in fluorescence microscopy and quantitative fluorescence workflows where bright, label-based readouts are required. In conjugate preparation, the NHS ester enables straightforward attachment to lysine residues and N-termini, supporting downstream imaging, cytometry, and assay development.

1. Protein And Antibody Labeling

Alexa Fluor488 NHS is routinely used by researchers to prepare fluorescently labeled proteins and immunoreagents for binding studies and fluorescence-based assays. Common workflows include labeling antibodies, antibody fragments, enzymes, and affinity reagents to generate fluorescent conjugates for target binding characterization, secondary antibody development, and reagent pairing in multiplex staining strategies. Because the NHS ester reacts with accessible primary amines, labeling is typically performed to generate amine-tagged conjugates that can be tracked by standard fluorescence microscopes and plate readers.

2. Fluorescence Microscopy Staining

Alexa Fluor488 NHS supports fluorescence microscopy experiments where lysine/N-terminal labeling of biomolecules is used to visualize binding to cells, extracellular matrices, or immobilized targets. Typical users include cell biology and biomaterials groups preparing fluorescent probes such as labeled ligands, uptake reporters, or surface-binding reagents for imaging on coverslips and in fixed-cell assays. The dye's visible-green emission aligns well with common filter sets, enabling straightforward integration into routine confocal and widefield microscopy pipelines for localization and colocalization studies.

3. Flow Cytometry Conjugate Preparation

Alexa Fluor488 NHS is frequently employed to generate flow cytometry dyes by labeling proteins and antibodies with a stable fluorescent tag that can be detected on standard cytometers. Researchers use these conjugates to quantify binding of fluorescent reagents to cell-surface markers, to monitor binding of labeled ligands, and to build multicolor panels by selecting compatible excitation/emission channels. Amine-reactive labeling supports consistent conjugate generation for staining workflows where fluorescent intensity readouts are used to compare populations under defined experimental conditions.

4. Fluorescent Bioassay Reagent Development

Alexa Fluor488 NHS is used in fluorescence assay development to create labeled assay components such as detection antibodies, protein tracers, and fluorescent standards for plate-based readouts. In typical applications, the labeled reagents enable signal generation through fluorescence intensity proportional to binding or reagent incorporation, supporting assay optimization and method development in chemical biology and analytical laboratories. The NHS ester format is particularly useful when fluorescent labeling must be introduced into proteins without requiring specialized dye-protein conjugation handles, streamlining reagent preparation for fluorescence-based screening and characterization.