Methods of inorganic polyphosphate (PolyP) assay in higher eukaryotic cells

Experimental investigation of polyP in higher eukaryotic organisms is a very challenging task. Levels of polyP in higher eukaryotes have several orders of magnitude lower compared to the levels of polyP in bacteria. Although many methods that were developed for studies of polyP in bacteria can be adapted for eukaryotes, some important points need to be considered in order to allow investigation of polyP in low abundance situations. In this chapter, we present an overview of the experimental methods of polyP assays in higher eukaryotes that are currently available. These methods include the biochemical approaches of polyP extraction and quantifi cation as well as fl uorescent imaging approaches that are suitable for polyP assays in the live tissue culture cells. We discuss advantages and limitations of each of the approaches. Finally, we describe the use of bacterial polyP metabolising enzymes as a tool for studies of polyP in eukaryotic cells.