Lactate Dehydrogenase (LD) Isoenzyme Panel

Testing requires a dedicated tube. Cannot be combined with other testing. Specimen must be aliquoted off after centrifugation.

Test Code

Quest Code

Alias/See Also

CPT Codes
83615, 83625

LD Isoenzymes (LD1, LD2, LD3, LD4, LD5)

Preferred Specimen
2 mL serum collected in a Serum Separator Tube (SST®)

Minimum Volume
1 mL

Centrifuge serum specimen within 1 hour of collection, transfer serum to clean, plastic, screw-capped vial(s), and transport at room temperature to the laboratory. Do not refrigerate or freeze the specimens. Specimens cannot be shared, and no other tests should be ordered with Lactate Dehydrogenase Isoenzymes.

Transport Temperature

Room temperature

Specimen Stability

Room temperature: 7 days
Refrigerated: Unacceptable
Frozen: Unacceptable

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Hemolysis • Received refrigerated • Received frozen

Electrophoresis • Spectrophotometry (SP)

Setup Schedule
Night Sets up 3 days a week.

Report Available
Reports in 2 to 3 days.

Reference Range
See Laboratory Report

Clinical Significance
Lactate dehydrogenase (LD) is present in many different organs and tissues such as liver, heart, muscles, kidney, lungs and blood. The usual designation of isoenzymes is LD-I, LD-II, LD-III, LD-IV and LD-V. LD isoenzymes tissue specificity is derived from the fact that LD subunits are synthesized in well-defined ratios and could be used in investigating unexplained causes of Total LD elevations and detection of macro-LD. Do not use LD isoenzymes to detect myocardial injury.

Performing Laboratory
Quest Diagnostics Nichols Institute
33608 Ortega Highway
San Juan Capistrano, CA 92690-6130

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.