C-reactive protein (CRP) by nephelometry (serum/plasma)
This test measures the level of C-reactive protein in your blood, a marker often used to check for inflammation or infection.
["CRP helps track inflammation, guiding decisions about treatment or further testing."]
Key facts at a glance
- LOINC
- 105787-6
- Short code
- OXA48PCR
- Synonyms
- blaOXA-48-like Ct Bld Pos Qn NAA+probe
- Category
- chemistry
- Sample
- whole-blood
- Container
- Positive blood culture broth from aerobic or anaerobic blood culture bottles (e.g., BACTEC, BacT/ALERT, VersaTREK bottles)
- Units
- N/A
- Ref low
- 15
- Ref high
- 40
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- probe-amp-tar
- CPT
- 87798
- SNOMED
- 122450008
- Specimen volume
- 1-2 mL of positive blood culture broth; testing performed directly from flagged-positive culture bottle
- Stability
- Stable for up to 24 hours at room temperature (15-25°C) and up to 72 hours at 2-8°C from the time of blood culture positivity flag. Avoid repeated freeze-thaw cycles. Transport promptly to laboratory.
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 1–8 hours
- Order
- routine
Why CRP Matters in Your Health
CRP is produced by your liver in response to inflammation. High levels may signal conditions like infections, autoimmune diseases, or tissue damage. It’s not specific to any single illness but can help doctors assess overall body response to injury or illness.
When This Test Is Ordered
Your doctor may order CRP to monitor chronic conditions (e.g., arthritis, heart disease), evaluate symptoms of infection, or check for signs of inflammation after surgery or injury. It’s sometimes used alongside other tests to guide treatment plans.
What to Expect Before the Test
No special preparation is needed, but you may be asked to fast for 8–12 hours before the blood draw if instructed by your provider. Wear comfortable clothing and plan to rest afterward.
What the Results Mean
Results are interpreted based on your health history and symptoms. Very high levels may prompt further testing, while low levels don’t always mean no inflammation is present. Your doctor will discuss findings with you.
Reference range
Negative for blaOXA-48-like carbapenem resistance gene. Ct (cycle threshold) values are reported as semi-quantitative measurements when positive; lower Ct values indicate higher bacterial load. Typical Ct values range from 15-40 cycles.N/A
No special patient preparation required. Sample should be collected prior to antimicrobial therapy initiation whenever possible to maximize detection sensitivity. Blood culture bottles should be collected using standard aseptic technique.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: CRP’s Role in Diagnosis and Management
Short name
CRP (Nephelometry)
Frequently asked questions
How often will I need this test?
Can lifestyle changes affect CRP levels?
What if my CRP is elevated?
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