*Confocal Laser Scanning Microscopy for Spectroscopic Studies of Living Photosynthetic Cells DOI: http://dx.doi.org/10.5772/intechopen.84825*

authors of the present chapter [3–5]. The technique is based on a strict relation between physiological state and genera affiliation of cyanobacterial cells and the intensity and the shape of corresponding single-cell fluorescence spectra, obtained by means of confocal microscopic spectroscopy. Light-, heat-, ultrasound- and toxin-induced changes can be distinguished by means of confocal microscopic spectroscopy since all these external actions are stress factors affecting photosynthetic process [5]. The application of such techniques for automation of on-line monitoring will give an additional opportunity to rise an effectiveness of biotechnological production and will bring in a valuable contribution to the development of innovative approaches in environmental monitoring [4, 5].

Here we present several experimental approaches to study the metabolic mechanisms in single photosynthetic cells in vivo. They are accompanied by several examples of in vivo investigations. Three main CLSM tools will be discussed in details: spectral imaging, fluorescent microscopic spectroscopy, and FRAP. All presented results were obtained using cyanobacterial strains from CALU collection of the Core Facility Center "Centre for Culture Collection of Microorganisms" of the Science Park of St. Petersburg State University as a model objects for CLSM studies.
