title: Spectrophotometric and electrochemical determinations of L(+)-lactate in blood by use of lactate dehydrogenase from yeast.
abstract: Lactate can be determined rapidly in blood by spectrophotometric and amperometric (enzyme electrode) procedures based on its oxidation by ferricyanide, the reaction being catalyzed with yeast L(+)-lactate dehydrogenase (cytochrome b2) (EC 1.1.2.3). In the photometric method lactate can be measured in a few minutes, but blood samples must first be deproteinized. In the amperometric procedure no treatment of blood is needed except ferricyanide addition. The enzyme electrode we used has a response time shorter than 1 min when its critical variables are optimized. Preliminary standardization is reduced to minimum operation, because electrode response is proportional to lactate concentration over a wide range (0.1 to 8.0 mol/liter) and many determinations can be done with little cost in enzyme. A simple electrical device ("two-electrode device") is described that is well suited for furture micro-cell construction. Lactate determinations on a series of normal blood samples show no deviation between results by these new methods and the usual ultraviolet spectrophotometric lactate tests.
mesh_terms: D000818:Animals; D004563:Electrochemistry; D006801:Humans; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D007773:Lactates / Q000097:blood*; D008722:Methods; D009132:Muscles / Q000201:enzymology; D010843:Pichia / Q000201:enzymology; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013237:Stereoisomerism
chemical_list: D007773:Lactates; D007770:L-Lactate Dehydrogenase