Home
HelpTest Code LD ISOENZ Lactate Dehydrogenase (LDH) Isoenzymes, Serum
Reporting Name
Lactate Dehydrogenase Isoenzymes, SUseful For
Investigating a variety of diseases involving the heart, liver, muscle, kidney, lung, and blood
Differentiating heart-synthesized lactate dehydrogenase (LDH) from liver and other sources
Investigating unexplained causes of LDH elevations
Detection of macro-LDH
Necessary Information
Patient's age is required.
Specimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 2 mL divided into 2 containers each containing 1 mL
Collection Instructions: Centrifuge and aliquot serum into 2 plastic vials, each containing 1 mL, within 2 hours of collection.
Specimen Type
SerumSpecimen Minimum Volume
0.75 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Ambient (preferred) | 7 days | |
| Refrigerated | 48 hours |
Day(s) Performed
Monday, Wednesday, Friday
TAT: 3 - 6 days
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Method Name
LDI: Electrophoresis Densitometry
LD: Photometric Rate Reaction
Method Description
Total Lactate Dehydrogenase:
Lactate and nicotinamide adenine dinucleotide (NAD[+]), in the presence of lactate dehydrogenase (LDH), 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: LDH reagent. Roche Diagnostics; 08/2019)
Isoenzyme:
The 5 isoenzymes of LDH are separated by electrophoresis on agarose film. The serum samples are electrophoresed and separated LDH isoenzymes are visualized using a specific chromogenic substrate. The amount of resulting formazan precipitate is proportional to the LDH enzymatic activity. Densitometry is used to obtain relative quantification of each fraction. The fractions are numbered according to their electrophoretic mobility, LDH-I being the most mobile.(Tietz NW, ed. Clinical Guide to Laboratory Tests. 3rd ed. WB Saunders Company; 1995; package insert: Sebia Hydragel ISO-LDH. Sebia; 07/2019)
Reference Values
LACTATE DEHYDROGENASE (LD)
1-30 days: 135-750 U/L
31 days-11 months: 180-435 U/L
1-3 years: 160-370 U/L
4-6 years: 145-345 U/L
7-9 years: 143-290 U/L
10-12 years: 120-293 U/L
13-15 years: 110-283 U/L
16-17 years: 105-233 U/L
≥18 years: 122-222 U/L
LD ISOENZYMES
I (fast band): 17.5-28.3%
II: 30.4-36.4%
III: 19.2-24.8%
IV: 9.6-15.6%
V (slow band): 5.5-12.7%
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
83615
83625
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| LD_I | Lactate Dehydrogenase Isoenzymes, S | 42929-0 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| LD | Lactate Dehydrogenase (LD), S | 14804-9 |
| 305 | LD Isoenzymes, S | 49279-3 |
| 3344 | Total LD Activity | 14804-9 |
| 2282 | I, Heart | 2536-1 |
| 2283 | II | 2539-5 |
| 2285 | III | 2542-9 |
| 2286 | IV | 2545-2 |
| 2287 | V, Liver | 2548-6 |
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| LD | Lactate Dehydrogenase (LD), S | Yes | Yes |
| LDI | LD Isoenzymes, S | No | Yes |
Report Available
3 to 6 daysReject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |