Tandem dyes are a unique class of fluorescent molecules that consist of two different covalently linked fluorophores, a donor (e.g. PE or APC) and a longer-wavelength emitting fluorescence acceptor (e.g. Texas Red, Cy5, Cy7, iFluor® 594 or iFluor® 750). APC-XFD750 tandem has the structure and properties similar to the commonly used APC-Alexa Fluor® 750. Its primary absorption peak is at 651 nm with emission peak at ~780 nm.

For an example antibody conjugation protocol, please see here.