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Serum or Plasma Substance Concentration (General Protein or Peptide Measurement)

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

This test measures the amount of a specific protein or peptide in your blood, either in serum or plasma, using a sensitive detection method.

Quick summary

["Your blood test helps assess protein function, health conditions, or metabolic processes."]

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

Key facts at a glance

LOINC
15306-4
Short code
Volume Testis-L from HWL
Synonyms
Volume Testis-L from HWL
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
us-derived-hwl
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

Doctors may order this test to diagnose or monitor conditions affecting protein levels, such as kidney disease, liver issues, infections, or certain cancers. It can also help track treatment responses or screen for genetic disorders.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if instructed. Bring any medications or supplements you’re taking, as they could affect results.

How the Test Is Performed

A healthcare provider will draw blood from a vein in your arm using a small needle. The blood sample is then sent to a lab for analysis using a high-sensitivity method, such as immunoassay or nephelometry.

Possible Results and Their Meaning

Results may indicate whether your protein levels are too high or too low compared to what’s typical for your body. Abnormal results can signal underlying health concerns that need further evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Protein/peptide level (serum/plasma)

Frequently asked questions

What Does an Abnormal Result Mean?
If your protein levels are elevated, it could suggest conditions like multiple myeloma, severe dehydration, or certain infections. If they’re low, it might point to kidney disease, liver problems, malnutrition, or immune disorders.
When Should You Follow Up?
If your test results are outside the expected range, your doctor will discuss next steps, which may include additional tests, lifestyle changes, or treatment adjustments based on your overall health.
Does This Test Have Any Risks?
The blood draw is generally safe but may cause mild bruising, soreness, or a slight pinch. Rarely, some people experience fainting or excessive bleeding. If you have a history of bleeding disorders, let your doctor know before the test.
  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