The Stokes shift is the difference between the absorption peak and the emission peak for fluorophores. Larger Stokes shift is always preferred as long as other properties of fluorescent probes are not compromised. Larger Stokes shift allows the use of broad excitation and emission filters that do not overlap, which increases brightness and sensitivity. Fluorescent probes of smaller Stokes shift requires filters that are very close together and do not include the entire area of the curves, thus reducing efficiency and brightness.