Ca2+-selective microelectrodes.
Ca2+-selective microelectrodes based on the synthetic neutral carrier ETH 1001 can be used for quantitative intracellular measurements of resting Ca2+-activities and of slowly changing Ca2+-levels (response time in the order of seconds). Microelectrodes with tip diameters greater than 0.3 micron show selectivities that yield a detection limit between 10(-8) and 10(-7) M Ca2+ in an intracellular background. The Ca2+-activity is obtained together with electrical parameters of the cell (e.g. cell membrane potential and membrane resistance or conductivity). Simultaneous monitoring of other ion-activities is accessible (double- or multi-barrelled microelectrodes). The Ca2+-determination is extremely local, i.e. it probably does not indicate an averaged cytosolic activity in every situation (e.g. localized transients).
D002118:Calcium / Q000032:analysis*; D002411:Cation Exchange Resins; D003593:Cytoplasm / Q000032:analysis*; D003959:Diamines; D004563:Electrochemistry; D008839:Microelectrodes / Q000592:standards; D011199:Potentiometry / Q000295:instrumentation; D013997:Time Factors
D002411:Cation Exchange Resins; D003959:Diamines; C045768:ETH 1001; D002118:Calcium