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Serum/plasma *substance concentration* probe for *Escherichia coli* (E. coli) antigens

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

This test detects the presence of *E. coli* bacteria in your blood or plasma by measuring specific antigens. It helps identify infections caused by these bacteria.

Quick summary

This test can help diagnose infections linked to *E. coli* in your bloodstream.

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

Key facts at a glance

LOINC
61401-6
Short code
P aerugns DNA Spec Ql NAA+probe
Synonyms
P aerugns DNA Spec Ql NAA+probe
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What This Test Measures

The test uses a probe to detect specific proteins (antigens) produced by *E. coli* bacteria. These antigens are unique to the bacteria and appear in your blood or plasma if an infection is present. The method involves an immunoassay to identify these markers.

Why It’s Done

Your healthcare provider may order this test if you have symptoms like fever, chills, or signs of a blood infection (sepsis), especially if you suspect *E. coli* is the cause. It can also be used in research or specialized diagnostic settings to confirm bacterial presence.

What to Expect Before the Test

No special preparation is typically needed. You may have a small needle inserted into a vein (venipuncture) to collect blood, or a sample may be taken from a different site if plasma is needed. If you’re on blood-thinning medication, inform your provider beforehand.

What the Results Mean

A positive result indicates the presence of *E. coli* antigens in your blood or plasma, suggesting an active infection. A negative result means no detectable antigens were found at the time of testing. Results may require confirmation with other tests.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

E. coli Antigen Test

Frequently asked questions

Early detection of *E. coli* in the blood is critical for prompt treatment with antibiotics or other therapies to prevent complications like kidney failure, shock, or organ damage. This test supports diagnosis in cases where symptoms are unclear or *E. coli* is suspected as the cause of infection.
This test is not a routine screening tool and is usually reserved for specific clinical situations, such as sepsis workups or research studies.
How accurate is this test?
The accuracy depends on the clinical context and whether the test is used for screening or confirmation. False negatives may occur if the infection is not severe enough to produce detectable antigens, or if the sample was collected too early. False positives are rare but possible if other infections or conditions are present.
Can I get this test at home?
No, this test is typically performed in a clinical laboratory setting using a blood or plasma sample collected by a healthcare professional. Home diagnostic tests for bacterial antigens are not standard for this specific analyte.
  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