An automated method for the determination of total lactate dehydrogenase, heat-stable lactate dehydrogenase isozyme-1, and hydroxybutyrate dehydrogenase
Strandjord, P.E.; Clayson, K.J.
Journal of Laboratory and Clinical Medicine 67(1): 131-143
ISSN/ISBN: 0022-2143 PMID: 5900722 Accession: 030012862
Recent studies with the isozymes of lactate dehydrogenase have demonstrated that LDH-1, the LDH isozyme which moves rapidly in an electrophoretic field, is particularly helpful in confirming the diagnosis of myocardial infarction. The determination of heat-stable LDH-1 and of hydrozybutyrate dehydrogenase, HBD, are two procedures which have been suggested for estimating LDH-1 activity. Accordingly, an automated method has been developed for determining the activity of total LDH and heat-stable LDH-1. If desired, the procedure is equally applicable to the determination of total LDH and HBD activity. The method depends upon an accurate determination of the rate of change of optical density which occurs as a result of coenzyme oxidation or reduction and does not rely on the use of commercially assayed enzyme standards. The procedure employs a spectrophotometer equipped with a flow cell, a recorder, and several modules of the AutoAnalyzer. The relative standard deviation, coefficient of variation, is 2.3 per cent.