ATTO 514 maleimide

ATTO 514 maleimide is a thiol-reactive fluorescent labeling reagent built on the ATTO 514 dye scaffold, enabling covalent attachment to cysteine-containing biomolecules through fast, selective maleimide chemistry. Its emission in the green-to-red region makes it a practical choice for fluorescence microscopy and flow cytometry workflows where robust conjugate formation is required. Researchers commonly use it to generate fluorescent protein, peptide, and antibody conjugates, as well as to label surfaces and biomaterials that present accessible thiol groups.

1. Biomolecule Thiol Labeling

ATTO 514 maleimide is frequently used by protein and peptide chemistry groups to fluorescently label cysteine-bearing targets for downstream imaging and quantitative fluorescence assays. In typical conjugate preparation workflows, the reagent is reacted with purified proteins, engineered peptides, or other thiol-functional biomolecules to produce stable thioether-linked fluorescent conjugates that can be tracked in solution or after immobilization. This labeling approach is especially useful when the experimental design requires covalent attachment rather than passive adsorption, supporting consistent signal readout in microscopy and assay development.

2. Fluorescence Microscopy Staining

ATTO 514 maleimide supports fluorescence microscopy applications where researchers need a bright, covalent thiol stain for fixed samples or labeled biomaterials. Cell biology and chemical biology laboratories often employ ATTO 514 maleimide to visualize thiol-functional components such as engineered proteins on cell surfaces, cysteine-tagged probes, or thiol-presenting extracellular matrix and scaffold materials. The maleimide handle allows direct incorporation of the dye into labeling reagents used for cellular imaging experiments, including colocalization studies with complementary fluorophores, leveraging the dye's emission for multiplex-friendly imaging designs.

3. Flow Cytometry Conjugates

ATTO 514 maleimide is used in flow cytometry workflows to generate fluorescently labeled biomolecules for cell-surface or extracellular labeling strategies that rely on accessible cysteine residues. Immunology and cell analysis laboratories commonly prepare ATTO 514 maleimide-conjugated antibodies, antibody fragments, or protein reagents to quantify binding to target-associated thiol-bearing constructs or to track labeled biomolecule uptake and association in suspension. Covalent labeling helps reduce variability from weakly associated fluorophores, supporting reproducible staining and consistent fluorescence measurements across experimental runs.

4. Biomaterial Surface Functionalization

ATTO 514 maleimide is widely applied in biomaterials research to fluorescently tag thiol-functional surfaces and matrices for imaging-guided material characterization. Materials scientists and biomaterial engineers use the reagent to label hydrogels, coatings, and surface-modified platforms that contain reactive thiol groups, enabling visualization of coating uniformity, spatial distribution, and conjugate retention. This use case is particularly valuable when the labeled material is later interrogated by fluorescence microscopy, allowing researchers to correlate material processing conditions with fluorescent labeling patterns and to validate surface functionalization strategies.