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Serum Isoleucine Mass Concentration

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of the amino acid isoleucine in your blood serum. Amino acids are the building blocks of proteins and play key roles in metabolism.

Quick summary

["Isoleucine levels help assess protein metabolism and potential amino acid imbalances."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
13402-3
Short code
Isoleucine Amn-mCnc
Synonyms
Isoleucine Amn-mCnc
Category
chemistry
Sample
fluid
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
2-5 mL
Stability
Room temperature: 2h, Refrigerated: 24h
Hemolysis max
300
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test if you have symptoms or conditions linked to amino acid disorders, such as unexplained muscle weakness, fatigue, or metabolic issues. It may also be part of a broader evaluation for genetic disorders affecting protein metabolism or liver/kidney function.

What Does the Test Involve?

A blood sample is drawn from a vein, typically in your arm. The blood is processed to separate serum (the liquid part without clotting factors), and the isoleucine concentration is measured using a specialized laboratory technique, often high-performance liquid chromatography (HPLC).

What Do Results Mean?

Results are not typically provided as a single reference range for isoleucine, as levels can vary widely depending on individual health, diet, and medical conditions. Your healthcare provider will interpret the result in the context of your symptoms, medical history, and other test results.

Common Conditions Monitored

Elevated or low isoleucine levels may be associated with conditions like aminoacidopathies (inherited metabolic disorders), liver disease, kidney disease, or certain genetic syndromes. However, isolated isoleucine abnormalities are less common and often require further evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Isoleucine Level

Frequently asked questions

What might cause abnormal results?
Abnormal isoleucine levels can result from metabolic disorders, severe liver or kidney disease, malnutrition, or certain medications. Genetic testing may be needed if your provider suspects an inherited condition.
How soon will I get results?
Results are typically available within 1 to 3 business days, depending on your lab’s processing time. Your healthcare provider will discuss the results with you during your follow-up visit.
Can diet affect this test?
Yes, diet can influence amino acid levels. High-protein diets or specific dietary restrictions (e.g., ketogenic diets) may temporarily alter isoleucine concentrations. Avoid eating or drinking anything (except water) for 8–12 hours before your test to ensure accurate results.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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