An image analysis system for fluorescence microscopy will be developed which incorporates state-of-the-art image acquisition technology. The project will result in the development of instruments and techniques for detailed biomass measurements of the pico- and nanoplankton components of the microbial food web. While video technology is the most common method of image acquisition, it is not particularly well suited for accurate, quantitative imaging in the low light environment of fluorescence microscopy. Video systems are limited by low sensitivity, non- linear response, and a narrow dynamic range. Digital cameras incorporating cooled, solid-state charged-coupled devices (CCDs), however, are now available with excellent characteristics of photon sensitivity, spatial and gray scale reolution, response linearity and quantum efficiency. These imaging devices overcome the major problems of video systems which limit their usefulness for quantitative image analyzed fluorescence microscopy. Development will be directed toward a system capable of ship- board use to allow rapid size spectra and biomass measurements of the bacteria and protists at sea as part of the Global Ocean Flux Study.
