... This lack of information is primarily due to technical difficulties in the monitoring of Cl in biological organisms. ... This restricts the duration of the measurements and allows only a very low data acquisition rate. 160 mM), which is relatively far from physiological range of Cl in mammalian nervous system (5-30 mM). Thus, development of molecules with sensitivities closer to this physiological range would provide a useful tool for monitoring Cl in biological preparations. ... Biological fac., ...