Lactate Dehydrogenase (LD) Isoenzymes, Serum
Method Description Describes how the test is performed and provides a method-specific reference
Lactate and NAD+, in the presence of LD, are converted to pyruvate and NADH. The rate at which NADH is formed is determined by an increase in absorbance and is directly proportional to enzyme activity. (Package insert: Roche LDH reagent, Indianapolis, IN, November, 1999)
The 5 isoenzymes of LD are separated by electrophoresis on agarose film. The serum samples are electrophoresed and separated LD isoenzymes are visualized using a specific chromogenic substrate. Densitometry is used to obtain relative quantification of each fraction. The fractions are numbered according to their electrophoretic mobility, LD-I being the most mobile.(Clinical Guide to Laboratory Tests. Third edition. Edited by NW Tietz, Philadelphia, WB Saunders Company,1995)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
LD: Monday through Sunday; Continuously
LD isoenzymes: Monday through Saturday; 10 a.m.