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Serum/plasma concentration of a generic protein or substance measured by immunoassay

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

This test measures the amount of a specific protein or substance in your blood, often used to check for infections, inflammation, or other health conditions.

Quick summary

["Helps diagnose and monitor various medical conditions by detecting specific proteins or substances in your bloodstream."]

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

Key facts at a glance

LOINC
71508-6
Short code
WEBSITE
Synonyms
—
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
esrd
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 This Test Is Done

Your healthcare provider may order this test to diagnose or monitor conditions such as infections (e.g., viruses, bacteria), autoimmune diseases, kidney or liver function, or other metabolic issues. It can also help track treatment responses or screen for hidden health problems.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it involves blood drawn from a vein. If you’re taking medications, let your provider know so they can advise whether to stop temporarily.

During the Test

A healthcare professional will draw blood from a vein in your arm. You may feel a slight pinch, but the procedure is quick. The blood sample is then sent to a lab for analysis using an immunoassay method to detect and measure the target protein or substance.

What the Results Mean

Results are compared to a general reference range, which can vary by lab and individual health. High or low levels may signal potential issues, but they often require additional testing or clinical correlation to determine cause and next steps.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Immunoassay Protein/Substance Level

Frequently asked questions

What does a high or low result mean?
A high level might indicate an active infection, inflammation, or overproduction of the protein/substance. A low level could suggest deficiency, reduced production, or kidney/liver issues. Your provider will discuss results in the context of your symptoms and medical history.
Can I eat or drink before this test?
Check with your provider first, as fasting may be required for some tests. Generally, you can drink water unless instructed otherwise. Avoid alcohol or certain medications that could interfere with results.
How long will I need to wait for my results?
Results are typically available within 1–3 business days, depending on lab processing times. Your provider will contact you once they’re ready for review and next steps.
  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