Dedecker, P., Flors, C., Hotta, J., Uji-i, H. and Hofkens, J.
3D nanoscopy: Bringing biological nanostructures into sharp focus. Angewandte Chemie International Edition 46: 8330-8332 (2007).

Ultrahigh-resolution microscopy is developing rapidly by different approaches. Photoactivation-localization microscopy (PALM) can now provide 3D images with fast acquisition times through the use of photoactivatable rhodamines and two-photon excitation. In PALM, individual emitters can be localized with nanometer precision simply by determining the centroid of the emission distribution.