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Serum or plasma concentration of arginine, measured by immunoassay

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

This test measures the amount of arginine, an essential amino acid, in your blood. Arginine plays a key role in protein synthesis, immune function, and detoxification processes.

Quick summary

["Arginine helps support your body’s natural processes and may be checked if you have conditions affecting metabolism or protein balance."]

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

Key facts at a glance

LOINC
31588-7
Short code
ENA RNP IgG Ser-aCnc
Synonyms
ENA RNP IgG Ser-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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

Why Might This Test Be Ordered?

Your healthcare provider may order this test if you have symptoms or conditions that could affect arginine levels, such as liver disease, kidney problems, or certain metabolic disorders. It may also be part of a broader evaluation for nutritional deficiencies or immune system issues.

What to Expect Before the Test

No special preparation is typically needed. If you’re having blood drawn, ensure you’re well-hydrated and avoid eating or drinking for 2–4 hours before the test if instructed. If you’re on a 24-hour urine collection, follow your provider’s specific instructions.

What to Expect During the Test

Blood is drawn from a vein, usually in your arm. The process is quick and may cause a slight pinch. If you’re having a urine sample collected, you’ll provide a timed urine specimen in a container provided by your lab.

What the Results Mean

Results are compared to standard reference ranges for healthy individuals. Abnormally low or high levels may signal underlying health concerns that need further evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Arginine Level

Frequently asked questions

How is arginine measured in the blood or urine?
Arginine levels are measured using an immunoassay, which detects the presence of arginine molecules in your blood or urine sample. This method is highly sensitive and accurate for identifying small changes in concentration.
What conditions might affect arginine levels?
Conditions like liver disease, kidney failure, or certain metabolic disorders (e.g., urea cycle disorders) can disrupt arginine metabolism, leading to elevated or low levels. Chronic infections, malnutrition, or medications (e.g., certain antibiotics or diuretics) may also influence arginine levels.
Do arginine levels change with diet?
Yes, arginine is found in many foods, including meat, dairy, and legumes. While diet can influence arginine levels, your body tightly regulates these levels, so dietary changes alone won’t drastically alter test results unless you have a known deficiency or metabolic disorder.
  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