IRDye 800CW Maleimide Can Label Molecules with Free Sulfhydryls.

IRDye® 800CW Maleimide

IRDye 800CW Maleimide Can Label Molecules with Free Sulfhydryls.

IRDye 800CW Maleimide provides the functionality for labeling molecules that contain free sulfhydryl (–SH) groups, such as cysteine residues in proteins, with IRDye 800CW. The reactive group of the IRDye 800CW Maleimide allows conjugation reactions to be performed very efficiently at physiological pH.

IRDye 800CW Maleimide reacting with a Thiol group
Maleimide reacting with a thiol group.

Dye Structure


  • Chemical Formula: C52H57N4Na3O16S4
  • Molecular Weight: 1191.25 g/mol
  • Exact Mass: 1190.23

Absorption and Emission Spectra

Solvent Ext. Coeff. (M-1cm-1) Absorption Maxima Emission Maxima
Methanol 300,000 778 nm 794 nm
Water 240,000 774 nm 789 nm
1X PBS 240,000 774 nm 789 nm
PBS: Methanol 270,000 777 nm 791 nm

Absorption and Emission Spectra in 1X PBS

IRDye 800CW Absorption and Emission Spectra

Selected P/N: 929-80020,929-80021,929-80050



Add to Cart

+ Add to WishlistAdded. Go to Wishlist

Generate an Autoquote


chat icon disabledLooking to chat with support? First, you will need to accept cookies.
Open Cookie Preferences
chat iconChat With Us
chat icon disabled