The photoactivatable fluorescent dye … … rhodamine NN, whose structure is shown in the cover picture, was combined with two further caged fluorophores with similar spectroscopic properties in a microscopy scheme for imaging cellular structures such as peroxysomes, actin, and microtubuli. The scheme, which uses only one emission and one detection channel, enables the stepwise activation and detection of the dyes. The synthesis and properties of rhodamine NN are described in the Communication by V. N. Belov et al. on page 3520 ff. (Picture: H. Sebesse, MPI für biophysikalische Chemie, Göttingen).