Skip to content

C-reactive protein (CRP) by line blot assay (qualitative/confirmatory)

Published: August 9, 2026Updated: August 16, 2026

This test checks for the presence of C-reactive protein, a marker often used to assess inflammation in your body.

Quick summary

["Determines if inflammation is present, helping guide treatment decisions."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
82390-6
Short code
CENPA
Synonyms
CENP A Ab Ser Line blot-aCnc
Category
chemistry
Sample
serum
Container
Serum separator tube (SST) or red-top tube
Units
N/A
Ref low
10
Ref high
15
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
line-blot
CPT
83516
SNOMED
1016741000122105
Specimen volume
0.5-1 mL serum
Stability
Stable for 7 days at 2-8°C; for longer storage, freeze at -20°C or below
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
24–72 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms of inflammation, such as fever, joint pain, or unexplained swelling. It could also be used to monitor conditions like infections, autoimmune diseases, or after certain treatments that affect inflammation levels.

What to Expect Before the Test

No special preparation is needed. You may have a blood sample drawn from a vein in your arm, similar to other routine blood tests. If you’re on blood thinners, discuss this with your provider first.

What the Results Mean

This test provides a qualitative result—meaning it only tells you if CRP is present (positive) or not (negative). It does not provide a quantitative measure of CRP levels, so it cannot show how high or low the protein is.

Common Uses and Limitations

While CRP is often used to screen for inflammation, this specific qualitative blot test is less commonly used in routine care. It may be reserved for situations where a more precise or confirmatory test is needed, such as in certain research or specialized clinical scenarios.

Reference range

Negative: <10 units; Equivocal: 10-15 units; Positive: >15 units. Reference values may vary by laboratory.N/A

Specimen: serum

No special preparation required. Sample may be collected at any time of day.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

CRP Blot Confirmation

Frequently asked questions

What does a positive CRP blot result indicate?
A positive result suggests inflammation is likely present in your body, which could be due to infection, injury, or an autoimmune condition. However, since this test is qualitative, it does not specify the cause or severity. Your provider will use this result alongside other clinical findings to guide further evaluation.
How does this test differ from a CRP blood test?
This test uses a line blot assay to detect CRP qualitatively, meaning it only identifies presence rather than measuring exact amounts. Traditional CRP blood tests (like quantitative immunoassays) provide numerical values to help assess inflammation levels more precisely.
Can I get this test at home?
No, this test is typically performed in a clinical or laboratory setting. Blood samples are collected by a healthcare professional, and results are interpreted by trained medical personnel.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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