title: Neutral carrier sodium ion-selective microelectrode for extracellular studies.
abstract: A Na+-selective microelectrode based on a synthetic neutral carrier (ETH 157) is described. The selectivities in respect to K+, Ca2+ and Mg2+ are adequate for extracellular measurements of Na+ activities. Microelectrodes with tip diameters of about 0.7 micron have an electrical resistance of 3 X 10(10) omega and a 90% response time of less than or equal to 3 s. The drift of the potential difference of the Na+-microelectrode cell assembly in aqueous extracellular electrolyte solutions is less than or equal to 0.2 m V/3 h.
mesh_terms: D000818:Animals; D001001:Anura; D001516:Bees; D002463:Cell Membrane Permeability; D004594:Electrophysiology / Q000295:instrumentation*; D005110:Extracellular Space / Q000378:metabolism*; D005123:Eye / Q000378:metabolism; D066298:In Vitro Techniques; D007668:Kidney / Q000378:metabolism; D008564:Membrane Potentials; D008839:Microelectrodes; D009482:Neurophysiology / Q000295:instrumentation*; D012964:Sodium / Q000378:metabolism*
chemical_list: D012964:Sodium