Lactate Dehydrogenase, Isoenzymes
Ordering Recommendation

Do not use to detect myocardial injury. Troponin I (0090613) and Troponin T (cTnT) 5th Generation (3001831) are the recommended tests for diagnosis and management of acute coronary syndrome. In rare cases, this test may be used to evaluate elevated lactate dehydrogenase associated with noncardiac muscle injury.

Quantitative Enzymatic/Electrophoresis
1-2 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
Serum Separator Tube (SST) or Plain Red. 
Specimen Preparation
Do not refrigerate or freeze. Allow specimen to clot completely at room temperature. Separate from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.6 mL) 
Storage/Transport Temperature
Room temperature. 
Unacceptable Conditions
Hemolyzed specimens. 
After separation of cells: Ambient: 1 week; Refrigerated: Unacceptable; Frozen: Unacceptable 
Reference Interval
LD-1: 14-27%
LD-2: 29-42%
LD-3: 18-30%
LD-4: 8-15%
LD-5: 6-23%

Lactate Dehydrogenase, Total:
0-1 month: 200-465 U/L
2-17 months: 200-450 U/L
18 months-10 years: 165-430 U/L
11-16 years: 127-287 U/L
17 years and older: 105-230 U/L
Interpretive Data

LD-1 and LD-2 are elevated in hemolyzed specimens and serum which has not been separated from cells.  LD-3, LD-4, and LD-5 are labile at low temperatures, and are erroneously low in specimens that have been refrigerated or frozen.
Hotline History
Component Test Code*Component Chart NameLOINC
0020015Lactate Dehydrogenase - 12536-1
0020016Lactate Dehydrogenase - 22539-5
0020017Lactate Dehydrogenase - 32542-9
0020018Lactate Dehydrogenase - 42545-2
0020019Lactate Dehydrogenase - 52548-6
0020107Lactate Dehydrogenase, Total14804-9
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please view this test within the Laboratory Test Directory found at
  • Isoenzymes
  • Isoenzymes of Lactate Dehydrogenase
  • Isoenzymes, LD
  • Lactate Dehydrogenase Isoenzymes, S
  • LD
  • LDH
  • LDH Fractionation
  • LDH Isoenzymes