title: Using the cytosensor microphysiometer to assess ocular toxicity.
abstract: Measuring in vitro cytotoxicity is one method currently used to estimate damage to the eye after chemical exposure. The Cytosensor Microphysiometer method evaluates cytotoxicity by measuring the test material-induced reduction in the metabolic rate of L929 cells. Changes in metabolic rate are measured indirectly as a function of changes in the extracellular acidification rate of the cells. During exposure to increasing concentrations of a cytotoxic material, there is a decrease in the release of acid byproducts into the surrounding medium as the cells die. These acidic metabolic byproducts cause a measurable change in the pH of a lightly buffered medium, which can be measured by the Cytosensor Microphysiometer. The change in the pH of the medium over time is then converted into a metabolic rate estimate for the cells. The endpoint measurement from the assay is the metabolic rate decline of 50%, the MRD50 value (in units of mg/ml).
authors.affiliation: Institute for In Vitro Sciences, Inc., Gaithersburg, Maryland.
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Nash
authors.forename: Greg
authors.initials: G
authors.lastname: Mun
authors.forename: Hans A
authors.initials: HA
authors.lastname: Raabe
authors.forename: Rodger
authors.initials: R
authors.lastname: Curren
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D002460:Cell Line; D005123:Eye / Q000187:drug effects*; D066298:In Vitro Techniques; D051379:Mice
keywords: Cytosensor Microphysiometer; eye irritation; in vitro cytotoxicity; metabolic rate; ocular irritation