Serum/plasma probe for *Escherichia coli* antigen (qualitative)
This test checks for the presence of *Escherichia coli* bacteria in your blood or plasma, often used to detect infections caused by this common gut bacterium that can sometimes spread to other parts of the body.
["A simple blood test to identify possible *E. coli* infections outside the digestive tract."]
Key facts at a glance
- LOINC
- 97631-6
- Short code
- P aerugns DNA Snv Ql NAA+n-prb
- Synonyms
- P aerugns DNA Snv Ql NAA+n-prb
- Category
- chemistry
- Sample
- fluid
- Container
- Sterile tube
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- non-probe-amp-tar
- Specimen volume
- 2-5 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h
- Hemolysis max
- 300
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms like fever, chills, or unusual fatigue combined with a recent infection (e.g., urinary tract, gastrointestinal, or wound). It helps determine if *E. coli* is the cause of a systemic (body-wide) infection beyond the usual site.
How the Test Works
The test detects specific proteins (antigens) produced by *E. coli* bacteria in your blood or plasma. If present, it confirms infection by this bacterium, though not all *E. coli* strains cause infections outside the gut.
Common Symptoms to Watch For
Symptoms like sepsis (severe infection spreading to blood), kidney issues, or unexplained fever may prompt this test. It’s not a routine screening test but is used in specific clinical scenarios.
What to Expect Before the Test
No special preparation is needed. A blood sample is drawn from a vein, similar to other routine blood tests. Results are qualitative (yes/no) rather than quantitative.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Positive results indicate *E. coli* infection in the bloodstream, which requires urgent medical attention. Negative results mean no detectable *E. coli* antigens were found, but other causes of symptoms must still be evaluated. This test is critical for guiding appropriate antibiotics or treatments.
Short name
E. coli Antigen Test (Qualitative)
Frequently asked questions
What does a positive result mean?
Can this test detect all types of *E. coli* infections?
Will I need follow-up tests if this test is positive?
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