Several key developments have occurred recently in the application of scanning probe microscopy to biology. These include the use of 'tapping-mode' atomic force microscopy both for the high-resolution imaging of biomolecules in liquids and for monitoring in situ biocatalysis, the use of atomic force microscopy as a force transducer to measure individual biological interactions, and the development of hybrid techniques such as scanning tunnelling microscopy coupled to confocal scanning laser microscopy.