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Serum Antibody to *Bacillus anthracis* (Anthrax) - Immunoassay

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

This test detects antibodies your immune system produces in response to exposure to *Bacillus anthracis*, the bacterium responsible for anthrax. It helps identify past or recent infection, even if symptoms aren’t present.

Quick summary

["This test checks for immunity to anthrax, useful after potential exposure or in certain high-risk settings."]

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

Key facts at a glance

LOINC
45142-7
Short code
ENA SS-B Ab Ser IA-aCnc
Synonyms
ENA SS-B Ab Ser IA-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
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

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you’ve had exposure to anthrax spores (e.g., occupational, travel-related, or bioterrorism risk), or if you’re part of a surveillance program for infectious diseases. It’s also sometimes used in research or public health investigations.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample from a vein in your arm. The test is typically done in a lab and results may take several days to weeks, depending on the lab’s processing time.

What the Results Mean

Positive results indicate the presence of anthrax antibodies, suggesting past exposure or infection. Negative results mean no detectable antibodies were found at this time. False negatives are possible, especially in early stages of infection.

Common Reasons for Testing

This test is primarily used for surveillance, research, or in high-risk populations (e.g., military personnel, lab workers, or travelers to endemic areas). It’s not typically part of routine health checks unless you’ve had a known exposure.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Anthrax Antibody Screening

Frequently asked questions

What does it measure?
This test measures the concentration of antibodies (immunoglobulins) your body produces in response to *Bacillus anthracis*. Antibodies are proteins that help your immune system recognize and fight the bacteria.
How is it used in diagnosis?
While this test can confirm past exposure or infection, it’s not used alone for diagnosing active anthrax. Instead, it’s often used alongside clinical symptoms, physical exams, and other diagnostic tests (like culture or PCR) to guide treatment decisions.
Could it affect my treatment?
No, this test itself doesn’t change your treatment. However, positive results may prompt further testing or monitoring, especially if you’ve had exposure. Always follow your healthcare provider’s advice based on your specific situation.
  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