Automated kinetic assay for lactate dehydrogenase isoenzyme 1 by centrifugal analysis after alkaline inactivation.
Lactate dehydrogenase isoenzyme 1 (LD1, EC 1.1.1.27) has been used widely as a marker for myocardial infarction, and many analytical methods for it have been developed, most of which are relatively labor intensive. On the basis of a recent report by Takizawa et al. (Clin Chem 29: 1941-1945, 1983) describing the marked stability of LD1 in buffered alkaline solutions, and with use of a centrifugal analyzer, we have developed a fully automated assay for LD1. Results with this method are precise (between-day SD = 2.1 U/L), vary linearly with LD1 activity to 600 U/L, and correlate well with LD1 as determined by immunological (Roche Isomune-LD) and agarose electrophoretic methods (r = 0.985 and 0.986, respectively). Furthermore, the method is easy and convenient, and should provide a substantial savings in labor and reagent costs to laboratories currently determining LD1 by electrophoretic or immunologic methods.
D001322:Autoanalysis; D002498:Centrifugation; D011232:Chemical Precipitation; D004587:Electrophoresis, Agar Gel; D004912:Erythrocytes / Q000201:enzymology; D005069:Evaluation Studies as Topic; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007120:Immunochemistry; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000097:blood*; D007773:Lactates; D019344:Lactic Acid; D009243:NAD; D011489:Protein Denaturation; D013050:Spectrometry, Fluorescence
D007527:Isoenzymes; D007773:Lactates; D009243:NAD; D019344:Lactic Acid; D007770:L-Lactate Dehydrogenase