title: Simultaneous determination of potassium and rubidium content in yeast.
abstract: Rubidium is widely used as a potassium analogue in transport studies in yeast and other organisms. As rubidium (potassium) uptake is modulated by the internal potassium concentration, it is often necessary to determine both Rb(+) and K(+) concentrations in the same cell extract. Current methods based on atomic absorption/emission spectroscopy require separate analysis for each cation. Alternatively, unsafe radioactive isotopes can be used. Here we report a convenient, non-radioactive, HPLC/conductivity-based method that allows a complete analysis of both cations with a single injection from a cell extract. The increase in Rb(+) uptake during K(+) starvation in yeast is easily demonstrated with this method.
authors.affiliation: Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-CSIC, Camino de Vera, 46022 Valencia, Spain.
authors.forename: Jose M
authors.initials: JM
authors.lastname: Mulet
authors.forename: Ramón
authors.initials: R
authors.lastname: Serrano
mesh_terms: D001693:Biological Transport, Active; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D008828:Microbiological Techniques; D011188:Potassium / Q000378:metabolism*; D012413:Rubidium / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism*
chemical_list: D012413:Rubidium; D011188:Potassium