title: A plug-in minielectrode for measurements in stirred photometric cuvettes.
abstract: A device is described to perform potentiometric measurements with ion-sensitive electrodes in stirred photometric cuvettes. Its design allows to make additions to the reaction medium with microliter syringes during measurements. Originally, this plug-in electrode was designed to register the free Ca2+ concentrations in the incubation medium of mitochondrial suspensions during measurements of the free matrix Ca2+ concentration with a permeant fluorescent Ca2+ indicator. However, numerous other applications can be easily realized, such as the combination of mitochondrial light-scattering measurements and ion-transport measurements, the combination of the permeabilized cell technique with fluorescence measurements of intracellular organelles or simply the calibration of the fluorescence of Ca2+ indicators with a Ca2+ ion-sensitive minielectrode. Compared with the use of a second fluorescent indicator the use of an electrode has the advantage that the signal can be transformed into ion concentrations already during the measurements.
authors.affiliation: Institute of Pharmacology and Toxicology, University of Göttingen, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Rustenbeck
authors.forename: S
authors.initials: S
authors.lastname: Lenzen
mesh_terms: D000814:Aniline Compounds; D000818:Animals; D002118:Calcium / Q000032:analysis* / Q000378:metabolism; D002122:Calcium Chloride / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D004566:Electrodes; D004867:Equipment Design; D005456:Fluorescent Dyes; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D008933:Mitochondrial Swelling; D011199:Potentiometry / Q000295:instrumentation* / Q000379:methods; D051381:Rats; D014966:Xanthenes
chemical_list: D000814:Aniline Compounds; D005456:Fluorescent Dyes; D014966:Xanthenes; C059715:Fluo-3; D004533:Egtazic Acid; D002122:Calcium Chloride; D002118:Calcium