MTS, TS, and maleimide, and other thiol-modifying reagents and reactive fluorescent dyes.

• Selection of thiol-reactive fluorescent dyes in a variety of colors
• Thiol-reactive cross-linkers and other modifiers
• Available with MTS, TS, and maleimide reactive groups
• Other thiol-reactive probes for specialized applications available

Biotium offers a variety of methanethiosulfonate (MTS) thiol modifying reagents and cross-linkers, as well as charged thiosulfate (TS) reagents for selectively modifying cell surface thiols.

In addition, we offer thiol-reactive probes for specialized applications. Eosin-5-maleimide is an thiol-reactive photosensitizer that can be used for photoconversion of electron-rich compounds like DAB or fluorescent dyes into electron-dense materials for high-resolution electron microscopy studies. It is also a good fluorescence acceptor for fluorescein, dansyl, and coumarin dyes for fluorescence resonance energy transfer (FRET). CPM (7-diethylamino-3-(4′-maleimidylphenyl)-4-methylcoumarin) is probably the most widely used blue fluorescent thiol-reactive dye. This maleimide derivative of coumarin is essentially nonfluorescent until it reacts with thiols, making it possible to quantify thiols without a separation step. ABD-F is a useful reagent for the sensitive and specific detection of thiols both by TLC and HPLC. When combined with a reducing agent such as tributylphosphine, it can also be used for the determination of disulfides in peptides and proteins. INA (5-iodonaphthyl-1-azide) is a lipophilic photoreactive probe, which has been used to selectively label membrane-embedded cysteine residues of proteins. N-(1,10-Phenanthrolin-5-yl)iodoacetamide has been used to label thiols to confer the metal-binding properties of the phenanthroline chelator. For example, completing of the chelator with copper can be used to selectively cleave RNA or DNA in the presence of hydrogen peroxide.

See Reactive Biotin Compounds for thiol-reactive biotinylation reagents. Also see our line of next-generation fluorescent CF™ Dyes, available in a wide selection of reactive dye formats, including thiol-reactive maleimide and MTS forms.

Texas Red is a registered trademark of Thermo Fisher Scientific.