Serum/plasma mass concentration of a substance measured by immunoassay (e.g., a marker related to protein or peptide levels)
This test measures the amount of a specific protein or peptide in your blood, often used to monitor conditions affecting protein levels or detect certain substances in the bloodstream.
["This test helps track protein or peptide levels that may indicate health concerns or treatment responses."]
Key facts at a glance
- LOINC
- 9811-1
- Short code
- CGA
- Synonyms
- CgA SerPl-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube; plasma may be collected in EDTA or heparin tubes
- Units
- N/A
- Ref low
- 0
- Ref high
- 36.4
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–99 years
- Method
- Immunoassay (typically ELISA, RIA, or chemiluminescent immunoassay)
- CPT
- 83519
- SNOMED
- 104847003
- Specimen volume
- 1.0 mL serum or plasma (minimum 0.5 mL)
- Stability
- Room temperature: 4 hours; Refrigerated (2-8°C): 24 hours; Frozen (-20°C or below): 6 months. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 50
- Lipemia max
- 100
- Icterus max
- 25
- TAT
- 24–96 hours
- Order
- routine
What This Test Measures
The test detects a particular protein or peptide in your blood, which may be involved in normal bodily functions, disease processes, or responses to medications. The exact substance can vary based on clinical need, but it often relates to proteins like hormones, enzymes, or other biologically active molecules.
Why It’s Ordered
Your healthcare provider may order this test to diagnose or monitor conditions such as protein-related disorders, infections, immune system issues, or to check for certain medications or toxins in your blood.
Sample Collection and Preparation
A blood sample is drawn from a vein, typically in your arm. The blood is then processed to separate serum or plasma, which is sent to the lab for testing. This process helps ensure accurate measurement of the target substance.
Test Results Interpretation
Results are reported as a mass concentration (e.g., grams per liter or micrograms per milliliter), though exact reference ranges depend on the specific protein or peptide being measured. Your healthcare provider will compare these results to your clinical situation and any known reference values for your test.
Reference range
Less than 36.4 ng/mL (cut-off value may vary by laboratory and assay method); Reference ranges are method-dependent.N/A
No fasting required. Proton pump inhibitors (PPIs) and H2-receptor antagonists should be discontinued at least 1-2 weeks prior to specimen collection as they can significantly elevate Chromogranin A levels. Patient should inform clinician of any medications including corticosteroids, antihistamines, or antacids.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
What causes abnormal results?
How often should I get this test?
Can lifestyle changes affect this test?
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 15, 2026. · Read our editorial policy