C-reactive protein (CRP) by nephelometry
This test measures the level of C-reactive protein, a protein produced by the liver in response to inflammation in your body.
["CRP helps doctors check for inflammation, which can signal infections, injuries, or other health issues."]
Key facts at a glance
- LOINC
- 106960-8
- Short code
- CD19FMC7
- Synonyms
- Cells.CD19+FMC7+ NFr Spec FC
- Category
- chemistry
- Sample
- serum
- Container
- Heparinized peripheral blood (sodium heparin or lithium heparin) or EDTA anticoagulant tube (for same-day processing); sterile tube for bone marrow or other body fluids
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- flow-cytometry
- CPT
- 86356 (individual marker); 86355 or 86357 may apply depending on panel composition
- SNOMED
- 444088001 (Flow cytometry) and related CD19/FMC7 immunophenotyping codes
- Specimen volume
- 3-5 mL peripheral blood in anticoagulant tube; minimum 1 mL for body fluid or bone marrow aspirate
- Stability
- Specimen must be processed within 24-48 hours of collection when stored at room temperature (18-22°C). Refrigeration may impair viability. Optimal viability maintained when analyzed within 6-8 hours of collection.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test to monitor conditions like infections, autoimmune diseases, or after surgery to see how your body is healing. It can also help track inflammation levels over time.
What Does a High or Low Level Mean?
Elevated CRP levels often indicate inflammation, which may be due to infections, injuries, or conditions like arthritis or heart disease. Very low levels might suggest no active inflammation, but they can also be affected by certain medications.
How Is This Test Performed?
A blood sample is taken from a vein, usually in your arm. The blood is then sent to a lab where it is analyzed using a special technique called nephelometry to measure CRP levels accurately.
What Should You Do Before the Test?
Avoid taking anti-inflammatory medications (like ibuprofen or aspirin) for at least 48 hours before the test, as they can affect your CRP levels. Also, inform your doctor if you have any conditions that might influence results, such as recent infections or surgery.
Reference range
Reported as percentage and absolute count of CD19+/FMC7+ B-lymphocytes within total lymphocytes or leukocyte population. Reference ranges are laboratory-specific and must be interpreted in clinical context.N/A
No fasting required. Specimen should be collected prior to chemotherapy, immunotherapy, or corticosteroid administration when possible, as these may alter lymphocyte subset distribution.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
CRP (Neph)
Frequently asked questions
Will I feel any pain or discomfort during the blood draw?
How long will it take to get my results?
Can I eat or drink before this test?
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