Product Description: PE-VF750 Maleimide is a thiol-reactive double-dye dye that contains maleimide groups that can react with thiol groups to form covalent bonds. Ex/Em=495-566/777 nm. PE-VF750 Maleimide contains two dyes, PE and VF, with excitation wavelengths (Ex) of 495 nm and 566 nm, respectively. PE-VF594 Maleimide has an emission wavelength (Em) of 777 nm.