CHEMICAL-ANALYSIS OF SINGLE CELLS AND EXOCYTOSIS

Recent advances in the development of microscale analytical techniques have allowed minute amounts of compounds of biological interest to be monitored in microenvironments. Microcolumn separation techniques, su ch as microcolumn liquid chromatography and capillary electrophoresis, provide a means of obtaining high-efficiency separations of analytes in picoliter to femtoliter volume samples. Voltammetric microelectrode techniques, such as amperometry and fast-scan cyclic voltammetry, are ideally suited for monitoring transiently occurring chemical events i n cellular and subcellular processes owing to their rapid response tim es and small structural dimensions. The principles and applications of these techniques in single-cell analysis are discussed throughout thi s review. Multicomponent separations and quantitations of large invert ebrate neurons of the land snail Helix neurons and the pond snail Plan orbis corneus dopamine neurons, and of small mammalian cells, bovine a drenal cells, rat PC12 cells, and human lymphocytes, by use of microco lumn liquid chromatography and capillary electrophoresis are presented . Electrochemical monitoring of neurotransmitter exocytosis from singl e adrenal cells, from PC12 cells, and from the cell body of the Planor bis dopamine neuron is highlighted. Results obtained from both separat ion and voltammetric techniques in single-cell analyses will provide a better understanding of cellular and/or neuronal chemistry and biolog y in complicated living environments.