Procalcitonin (PCT) in serum/plasma
This test measures procalcitonin, a precursor protein of calcitonin, which is produced by cells in response to bacterial infections. It helps distinguish between bacterial and viral infections.
["Procalcitonin helps guide antibiotic use and assess serious infections."]
Key facts at a glance
- LOINC
- 34528-0
- Short code
- PT Pnl PPP
- Synonyms
- PT Pnl PPP
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- coag
- CPT
- 85610
- SNOMED
- 396252006
- 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
What Is Procalcitonin Used For?
Procalcitonin is primarily used to identify bacterial infections, especially in cases where other tests like C-reactive protein (CRP) may not be definitive. It can also help monitor treatment responses in patients with sepsis or severe infections.
When Might You Need This Test?
Your doctor may order a procalcitonin test if you have symptoms like fever, chills, or signs of infection (e.g., pneumonia, sepsis, or severe illness). It’s often used in hospital settings to assess suspected bacterial infections.
How Is the Test Performed?
A blood sample is drawn from a vein, usually in your arm. The sample is then sent to a lab for analysis using an immunoassay method to measure procalcitonin levels.
What Do Results Mean?
Elevated procalcitonin levels often signal bacterial infection, while lower or normal levels may suggest viral infection or no active bacterial infection. Your doctor will interpret results in the context of your symptoms and medical history.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Procalcitonin plays a key role in differentiating bacterial from viral infections, reducing unnecessary antibiotic use, and improving patient outcomes in critical care settings.
Short name
PCT (Serum/Plasma)
Frequently asked questions
Why is procalcitonin sometimes ordered alongside CRP?
Can procalcitonin levels change with treatment?
Does diet or exercise affect procalcitonin levels?
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 16, 2026. · Read our editorial policy