title: Automated enzymatic determination of L-lactate in serum, with use of a miniature centrifugal analyzer.
abstract: We describe an automated enzymatic reaction-rate method for spectrophotometric determination of lactate in serum with a miniature centrifugal analyzer. The L(+) -lactate is selectively oxidized in the presence of lactate dehydrogenase (EC 1.1.1.27) and NAD+ to form NADH, which is measured from its absorption. Reaction rates are determined automatically, and unknown concentrations are calculated from a computer-generated calibration curve with aqueous lithium lactate standards. Lactate concentrations in the range 0.32-1.6 mug/4 mul (80-400 mg/liter) of sample were determined with relative errors and coefficient of variation of 4.8%. Analytical recovery of lactate added to pooled serum was 89-112% (average, 101%). Comparison with a kit ("Rapid Lactate") method gave a correlation coefficient squared of 0.979 over a concentration range of 39-779 mg/liter.
mesh_terms: D001322:Autoanalysis; D002498:Centrifugation; D006801:Humans; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D007773:Lactates / Q000097:blood*; D008832:Microchemistry; D012769:Shock / Q000097:blood; D013053:Spectrophotometry; D013696:Temperature
chemical_list: D007773:Lactates; D007770:L-Lactate Dehydrogenase