Mercapto Reactive Dyes

NBD-X acid is a fluorescent probe containing a nitrobenzoxadiazole group. NBD-X acid can be used to study the structure and function of biomolecules.

DACM (N-(7-Dimethylamino-4-methyl-3-coumarinyl)maleimide) is a thiol-directed fluorescent dye (Ex=396 nm, Em=468 nm).

FM-red (PSH-red) is a red-emitting and environment-sensitive probe for selectively detecting and labeling protein thiols. FM-red can be used to image protein sulfhydryl groups in live cells and in vivo. FM-red also could be used to measure of the redox states of thioredoxin (Trx).

Fluorescein-5-maleimide (solution) (N-(5-Fluoresceinyl)maleimide (solution)) is a fluorescent dye. Fluorescein-5-maleimide can be used to detect the redox state of thiols in eukaryotic cells. Fluorescein-5-maleimide can label peptides and is used to detect negatively charged nanoparticles. Fluorescein-5-maleimide can also label actin to explore its interaction with cardiac myosin-binding protein C (cMyBP-C), which helps in developing small molecule modulators for heart failure. Fluorescein-5-maleimide can screen mutant proteins that contain cysteine residues. The excitation wavelength of Fluorescein-5-maleimide is 494 nm, and the emission wavelength is 519 nm.

Solvent and concentration: DMSO: 10 mM

NFQ1 is a non-fluorescent quencher (absorption wavelength: 474 nm), and is used for a new type of One Sample Fluorescence Resonance Energy Transfer (OS-FRET) method. OS-FRET enable measurement of unquenched donor emission in the same sample. NFQ1 shows broad absorption spectrum ensuring its utility as a dark acceptor for many donors.

7-Fluorobenzofurazan-4-sulfonic acid ammonium is a fluorescent label. 7-Fluorobenzofurazan-4-sulfonic acid ammonium can be used for detecting dissolved thiol-disulfide (e.g., Cys, GSH).

SEluc-2 is a small-molecule probe based on the firefly luciferin. SEluc-2, a bioluminescent probe for the sensitive and selective detection of thiols in living cells.

DCI-Br-3 is a rapid, highly sensitive, and selective probe to monitor thiols in the epileptic brain. (λ_ex=537 nm, λ_em=675 nm).DCI-Br-3 can effectively cross the blood-brain barrier (BBB).

AF532 C5 Maleimide is a Fluorescent dye used for protein labeling. AF532 C5 Maleimide covalently binds to thiol groups via its maleimide moiety. AF532 C5 Maleimide can label VASP to support visualization studies in phase separation and focused actin polymerization experiments.

AF488 C5 Maleimide is a thiol-reactive Fluorescent dye used to label target proteins and bacterial structures. AF488 C5 Maleimide irreversibly forms covalent thioether conjugates with cysteine ​​thiol groups. AF488 C5 Maleimide stabilizes pre-formed globular low-molecular-weight Tau protein oligomers by blocking cysteine-dependent tau protein aggregation, allowing observation of the internalization process of tau protein oligomers into neuronal cells via confocal microscopy. AF488 C5 Maleimide can label cysteine-modified pili; the outer membrane permeability varies among different bacterial species, allowing imaging via epifluorescence microscopy using a FITC filter set.

BADAN is a thiol-reactive, environment-sensitive fluorescent probe used for site-specific labeling of protein cysteine residues to detect protein topology, local polarity, protein-lipid interactions, and conformational changes. The bromoacetyl group of BADAN covalently binds to cysteine thiols, and its fluorescence originates from the intramolecular charge transfer (ICT) excited state. The emission peak position varies with the polarity of the surrounding medium: it blue-shifts to approximately 488 nm in nonpolar environments (such as the hydrophobic core of lipid bilayers) and red-shifts to approximately 496-507 nm in polar environments (such as aqueous phases), independent of enzymes, pH, or membrane potential. Ex = 380-402 nm; Em = 400-600 nm.

AF633 C5 Maleimide is a fluorescent dye used for surface protein labeling of extracellular vesicles and peptide labeling. AF633 C5 Maleimide covalently binds to protein thiol residues under neutral pH conditions (6.5-7.5), enabling visualization and quantitative analysis of extracellular vesicle uptake by target cells. AF633 C5 Maleimide undergoes maleimide-cysteine conjugation with cysteine residues on peptides in acetonitrile-water buffer solution, supporting detection of peptide-functionalized gold nanorods via confocal laser scanning microscopy, as well as tracking their cellular uptake and localization.

AF568 C5 Maleimide is a bright orange-red thiol-reactive fluorescent dye. AF568 C5 Maleimide selectively labels the thiol groups on cysteine residues in proteins, peptides and antibodies via stable thioether bonds (Ex/Em = 575/600 nm).

AF700 PEG12 Maleimide is a derivative of Alexa Fluor 700 featuring a maleimide reactive group for conjugation with thiol groups. It incorporates a PEG12 linker to enhance hydrophilicity and provide increased spacer length. AF700 PEG12 Maleimide is primarily used for labeling thiol-containing proteins or peptides (Ex/Em = 702/723 nm).

AF430 C2 Maleimide is a derivative of Alexa Fluor 430 featuring a maleimide reactive group, used for conjugation and labeling via thiol groups. It is primarily applied to the labeling of thiol-containing proteins and peptides (Ex/Em = 434/539 nm).

AF430 PEG12 maleimide is a derivative of Alexa Fluor 430 featuring a maleimide reactive group for conjugation with thiol groups. It incorporates a PEG12 linker to enhance hydrophilicity and provide spacer distance. AF430 PEG12 maleimide is primarily used for labeling thiol-containing proteins or peptides (Ex/Em = 434/539 nm).

AF660 C2 Maleimide is a derivative of Alexa Fluor 660 featuring a maleimide reactive group, designed for conjugation with thiol groups. AF660 C2 Maleimide can be used to label thiol-containing proteins or peptides (Ex/Em = 663/690 nm) .

Methylene blue maleimide is a derivative of a thiazine dye featuring a reactive maleimide group, used for conjugation and labeling via sulfhydryl groups. It is suitable for labeling proteins or peptides containing sulfhydryl groups (Ex/Em = 664/682 nm) .

AMCA-PEG4-Mal is a derivative of AMCA featuring a maleimide reactive group for thiol-based conjugation and labeling. It incorporates a PEG4 linker to enhance solubility and minimize steric hindrance. AMCA-PEG4-Mal is suitable for labeling thiol-containing proteins or peptides (Ex/Em = 347/444 nm).

MMBC is a sulfhydryl-sensitive fluorophore.