Product Description: PE-VF680 Maleimide is a double-dye dye that can undergo thiol reaction. It contains maleimide groups that can react with thiol groups to form covalent bonds. Ex/Em=495-566/701 nm. PE-VF680 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 701 nm.