C-reactive protein (CRP) by nephelometry
This blood test measures the level of C-reactive protein, a protein produced by the liver in response to inflammation or infection.
["CRP helps track inflammation in your body."]
Key facts at a glance
- LOINC
- 105031-9
- Short code
- OXA58
- Synonyms
- blaOXA-58 Islt/Spm Ql
- Category
- chemistry
- Sample
- serum
- Container
- Sterile, leak-proof container or transport medium appropriate for the specimen type (e.g., Amies or Stuart transport medium for swabs; sterile tube for serum)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- molgen
- CPT
- 87150 (Culture, typing; identification by nucleic acid amplification method) or 87153 (for confirmation); specific CPT may include 87798 (amplification, multiplex)
- SNOMED
- 122440007
- Specimen volume
- Minimum 0.5-1 mL serum or per specimen type requirements
- Stability
- Specimen stable for 24 hours at room temperature; up to 5 days at 2-8°C; for prolonged storage, freeze at -70°C or below. For serum: stable 8 hours at 15-25°C, 48 hours at 2-8°C, longer at -20°C.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–48 hours
- Order
- routine
Why Is This Test Done?
Doctors may order a CRP test to check for signs of inflammation, monitor conditions like arthritis, heart disease, or infections, or evaluate how well a treatment is working. It can also help diagnose or monitor certain autoimmune diseases.
What Does a High CRP Level Mean?
Elevated CRP levels often indicate inflammation, which can be caused by infections, injuries, or inflammatory diseases. However, it’s not specific to any one condition, so results are usually interpreted alongside other symptoms and tests.
What Does a Low CRP Level Mean?
Low CRP levels usually mean there is little to no inflammation in your body. However, very low levels might not always indicate a healthy state, especially if you have certain chronic conditions.
How Is This Test Performed?
A small sample of blood is drawn from a vein in your arm. The blood is then analyzed in a lab using nephelometry, a method that measures how much light a protein scatters.
Reference range
Negative (blaOXA-58 gene not detected). Results reported qualitatively as Detected or Not Detected.N/A
No special patient preparation required. Specimen should be collected prior to initiation of antibiotic therapy whenever possible to maximize detection yield.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
CRP (Neph)
Frequently asked questions
What does a CRP test measure?
How long does it take to get CRP test results?
Can CRP levels be affected by diet or exercise?
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