IRDye® 650 Maleimide

IRDye 650 Maleimide

IRDye 650 Maleimide is an infrared dye with detection near 650 nm. Maleimide reactive group provides the functionality for labeling molecules that contain free sulfhydryl (–SH thiol) groups. This reactive group allows conjugations reactions to be performed at physiological pH.

This dye is not suitable for use with LI-COR Odyssey® Imaging Systems.

IRDye Infrared Dyes Overview
IRDye 650 Maleimide reacting with a Thiol group

Dye Structure

IRDye 650 Maleimide structure


  • Chemical Formula: C48H53N4Na3O15S4
  • Molecular Weight: 1123.17 g/mol
  • Exact Mass: 1122.21

Absorption and Emission Spectra

Solvent Ext. Coeff. (M-1cm-1) Absorption Maxima Emission Maxima
Methanol 240,000 651 nm 668 nm
1X PBS 230,000 648 nm 665 nm
PBS: Methanol 230,000

Absorption and Emission Spectra in 1X PBS

IRDye 650 Absorption and Emission Spectra

To discuss purchase quantities over 1 gram or commercial development rights using IRDye infrared dyes, please contact Business Development.

Selected P/N: 929-71014,929-71015



Add to Cart

+ Add to WishlistAdded. Go to Wishlist


    chat iconChat With Us
    chat icon disabled