The development of the first practical confocal laser scanning microscope in the 1980's was a major advance in optical microscopy. These microscopes allow researchers to obtain optical sections from intact specimens up to a depth of several hundred microns, and are now widely used in plant biology for the visualisation of biological processes and ultrastructure in intact and living plant tissues. A successful JREI application in 1998 led to the installation of an early generation confocal microscope in the Department of Plant Sciences in the University of Cambridge. As a result, plant researchers here have contributed heavily to the early development and application of confocal imaging techniques. Our existing facilities need upgrading in order to maintain our lead in the development of new fluorescent proteins, transgenic marker lines in Arabidopsis, algal and crop systems, new microtechniques for 3D imaging, software for image segmentation, visualisation and quantitation, and the application of advanced optical techniques to the analysis of cell, protein and metabolite dynamics in a wide variety of algal and plant systems.