Intracellular pH of halobacteria can be determined by the fluorescent dye 2', 7'-bis(carboxyethyl)-5(6)-carboxyfluorescein.
Determination of the internal pH of halobacterial cells grown in 4M salt solution has proven to be a difficult problem. We now report the steady state cytosolic pH of Halobacterium halobium S-9 to be 7.2. Intracellular pH was determined after the cells were loaded with the membrane permeable precursor of the pH sensitive dye 2', 7'-bis-(carboxyethyl)-5(6)-carboxyfluorescein-acetyxymethyl ester - (BCECF/AM). In order to minimize light-scattering in the measurement of the fluorescence, a thin cuvette was newly devised. This method should be suitable for studies of the cytosolic pH in other bacteria.
Lawrence Berkeley Laboratory, University of California, Berkeley 94720.
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Tsujimoto
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Semadeni
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Huflejt
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Packer
D001826:Body Fluids / Q000378:metabolism*; D002138:Calibration; D003600:Cytosol / Q000378:metabolism; D005452:Fluoresceins; D006217:Halobacterium / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007424:Intracellular Fluid / Q000378:metabolism*; D008985:Monensin; D012965:Sodium Chloride; D013050:Spectrometry, Fluorescence
D005452:Fluoresceins; D007202:Indicators and Reagents; C024098:6-carboxyfluorescein; D012965:Sodium Chloride; D008985:Monensin