LD_I - Performance: Lactate Dehydrogenase (LD) Isoenzymes, Serum

Test Catalog

Test Name

Test ID: LD_I    
Lactate Dehydrogenase (LD) Isoenzymes, Serum

Method Description Describes how the test is performed and provides a method-specific reference

Photometric Rate:

Lactate and NAD+, in the presence of lactate dehydrogenase (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)


Isoenzyme Electrophoresis:

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)

PDF Report Indicates whether the report includes an additional document with charts, images or other enriched information


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: Tuesday, Thursday, Saturday; 10 a.m.

Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.

1 day-LD Total ; 3 days- LD Isoenzymes

Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result

2 days-LD Total; 4 days-LD Isoenzymes

Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

1 week

Performing Laboratory Location The location of the laboratory that performs the test