Lactate Dehydrogenase 5 (LDH-5) Fraction, Serum or Plasma, by Electrophoresis
This test measures the proportion of total lactate dehydrogenase (LDH) made up by the LDH-5 isoenzyme in serum or plasma. Electrophoresis separates the LDH isoenzymes so the LDH-5 fraction can be identified.
["An increased LDH-5 fraction may indicate liver or other tissue injury, but results must be interpreted with the total LDH level and your clinical situation."]
Key facts at a glance
- LOINC
- 2548-6
- Short code
- LDH5 CFr SerPl Elph
- Synonyms
- LDH5 CFr SerPl Elph
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 140
- Ref high
- 280
- Critical range
- 7.2 N/A – 7.6 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- electrophoresis
- CPT
- 83615
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What Does This Test Measure?
LDH is an enzyme found in many tissues, including the liver, muscles, heart, blood cells, and other organs. This test identifies the LDH-5 isoenzyme and reports it as a fraction of the total LDH activity.
Why Is the Test Performed?
It may be ordered as part of an evaluation of an unexplained elevated LDH level or when liver, muscle, blood-cell, or other tissue injury is suspected. It is usually interpreted alongside other laboratory and imaging results.
How Is the Sample Tested?
A serum or plasma sample is analyzed by electrophoresis, which separates the LDH isoenzymes according to their electrical properties. The laboratory then determines the proportion represented by LDH-5.
What Do Results Mean?
A higher LDH-5 fraction can occur with liver-cell injury and may also be associated with tissue damage, including certain cancers or muscle injury. A lower or normal fraction does not by itself rule out disease, and isolated results should not be used to make a diagnosis.
Reference range
Adult: 140-280 U/LN/A
No special preparation required. Inform provider of any chest pain or symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical significance: An elevated LDH-5 fraction may support the presence of tissue injury, particularly involving the liver, but it is not specific to one condition. Interpret the result with total LDH, other blood tests, symptoms, medical history, and relevant imaging; consult the ordering clinician for an individualized explanation.
Short name
LDH-5 fraction
Frequently asked questions
Does a high LDH-5 fraction diagnose liver disease?
What is the difference between an LDH-5 fraction and a total LDH level?
Can medications or exercise affect this result?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy