DY-680-NHS ester is an amine-reactive, hydrophilic fluorescent dye. It efficiently conjugates with antibodies at high degrees of labeling (D/P ratios) without causing fluorescence quenching or precipitating the conjugates. This compound is widely used in applications such as protein blotting, microscopy, flow cytometry, and cell-based assays. Its spectral properties include an excitation wavelength of 690 nm and an emission wavelength of 709 nm.