22/08/2025
CRP Test (C-Reactive Protein Test):
1. Objective
To detect and measure the concentration of C-reactive protein (CRP) in a patient's blood, which helps indicate the presence and intensity of inflammation or infection in the body.
2. Principle
The CRP test is based on the agglutination reaction between CRP in the patientβs serum and latex particles coated with anti-CRP antibodies. If CRP is present, visible clumping occurs.
Qualitative CRP Test: Detects presence of CRP.
Quantitative CRP Test: Measures CRP concentration using nephelometry, turbidimetry, or immunoassay.
3. Materials Required
CRP latex reagent (antibody-coated latex particles)
Positive and negative control sera
Patient serum sample
CRP test card or slide
Mixing sticks or applicators
Micropipette/dropper
Timer
Light source (optional)
4. Procedure (Qualitative CRP Test)
1. Bring reagents and serum to room temperature.
2. Place a drop of patient serum on the test card.
3. Add one drop of CRP latex reagent next to it.
4. Mix well with an applicator.
5. Gently rock the card for 2 minutes.
6. Observe for visible agglutination
5. Result (Example)
Sample Observation Interpretation
Positive Ctrl Agglutination Valid
Negative Ctrl No agglutination Valid
Patient Serum Agglutination seen CRP positive (inflammation)
For quantitative test, results are given in mg/L.
Normal: < 6 mg/L
Mild inflammation: 6β40 mg/L
Moderate to severe: 40β200+ mg/L
6. Uses
Diagnose or monitor infections, inflammatory diseases, autoimmune disorders.
Detect bacterial vs viral infections (CRP is usually higher in bacterial infections).
Monitor treatment response (e.g., in sepsis or arthritis).
Assess risk of cardiovascular disease (via high-sensitivity CRP or hs-CRP).
7. Conclusion
The CRP test is a rapid, sensitive tool for identifying inflammation or infection. Qualitative tests detect the presence of CRP, while quantitative tests help measure its severity. It should be interpreted in conjunction with clinical signs and other laboratory findings.
