title: A microphysiometer for simultaneous measurement of changes in extracellular glucose, lactate, oxygen, and acidification rate.
abstract: A microphysiometer capable of measuring changes in extracellular glucose, lactate, oxygen, and acidification rate has been developed by incorporating modified electrodes into a standard Cytosensor Microphysiometer plunger. Glucose and lactate are measured indirectly at platinum electrodes by amperometric oxidation of hydrogen peroxide, which is produced from catalysis of glucose and lactate at films containing their respective entrapped oxidase. Oxygen is measured amperometrically at a platinum electrode coated with a Nafion film, while the acidification rate is measured potentiometrically by a Cytosensor Microphysiometer. Analytical information is obtained during the Cytosensor stop-flow cycles, where the electrodes measure changes in the extracellular medium corresponding to the consumption or production of the analyte by the cells. Modification of the Cytosensor plunger for multianalyte determination is described, and the operation of the technique is illustrated by the simultaneous measurement of all four analytes during the addition of fluoride and DNP to Chinese hamster ovary cells and fluoride and antimycin A to mouse fibroblast cells. Cell metabolic recovery and dynamics after exposure to agents can also be observed in specific cases.
authors.affiliation: Department of Chemistry, and Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University, VU Station B, Nashville, Tennessee 37235, USA.
authors.forename: Sven E
authors.initials: SE
authors.lastname: Eklund
authors.forename: Dale
authors.initials: D
authors.lastname: Taylor
authors.forename: Eugene
authors.initials: E
authors.lastname: Kozlov
authors.forename: Ales
authors.initials: A
authors.lastname: Prokop
authors.forename: David E
authors.initials: DE
authors.lastname: Cliffel
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000592:standards; D016466:CHO Cells; D006224:Cricetinae; D004566:Electrodes; D005110:Extracellular Space / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D005947:Glucose / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000032:analysis*; D051379:Mice; D010100:Oxygen / Q000032:analysis*; D010984:Platinum / Q000737:chemistry; D012680:Sensitivity and Specificity
chemical_list: D019344:Lactic Acid; D010984:Platinum; D005947:Glucose; D010100:Oxygen