Three-dimensional imaging with a confocal microscope is probably the most advanced imaging method that can be applied to living cells. As equipment becomes ever more sophisticated, the application of confocal microscopy of living cells has become increasingly common and productive. Unfortunately, such studies usually require the introduction of fluorescent dyes into the cell and when these are illuminated with the laser beam of the confocal microscope, the dye molecules are often degraded in a manner that injures the living cell. Though much has been written about this problem when viewing living cells, the solution comes down to making the best possible use of the fluorescent light photons emitted by the dye. Photon efficiency has two aspects: ensuring that as many photons as possible reach the detector in a short period of time and making sure that those that do so are actually detected. Recently a silicon photodetector has been designed (available in several different formulations) which operates at high efficiency in collecting and detecting photons. Dr. Pawley proposes to modify these detectors for use in a confocal microscope and test their performance under realistic conditions to determine the optimum design and method of adaptation. The final adaptation should be a signal advance in the technique of three-dimensional visualization of cells.
