Serum Diphtheria Toxin Antibody, Qualitative (IgG)
This test checks for the presence of antibodies in your blood that help your immune system fight diphtheria, a serious bacterial infection.
["Knowing your antibody levels can help determine if you’ve been protected against diphtheria after vaccination or exposure."]
Key facts at a glance
- LOINC
- 53932-0
- Short code
- S pn 14 seros+C diph+C tet IgG Pnl Ser
- Synonyms
- S pn 14 seros+C diph+C tet IgG Pnl Ser
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 36
- Ref high
- 50
- Critical range
- 18 N/A – 60 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85014
- 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 Is Done
Doctors may order this test if you’ve had recent exposure to diphtheria, if you’re planning travel to areas with higher infection rates, or if you’re unsure about your vaccination status. It can also help monitor immunity after vaccination.
What to Expect Before the Test
No special preparation is needed. You’ll have a small needle inserted into your arm to draw blood. The process takes a few minutes, and you may feel a brief pinch. If you’re nervous, let your healthcare provider know.
What the Test Results Mean
A positive result means you have antibodies against diphtheria toxin, indicating your immune system has likely been exposed or vaccinated. A negative result suggests you may not have adequate immunity and could benefit from vaccination.
Possible Side Effects
Most people experience mild side effects like a small bruise, slight pain, or swelling at the injection site. These usually go away within a day or two. Rarely, you might have a fever or headache.
Reference range
Adult males: 38-50%; Females: 36-44%N/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is primarily used to assess immunity status against diphtheria. A positive result confirms protection, while a negative result may prompt vaccination or booster doses. It’s especially important for individuals at higher risk, such as travelers, immunocompromised patients, or those in areas with limited vaccination coverage.
Short name
Diphtheria Toxin Antibody (IgG) Test
Frequently asked questions
What does a positive result mean for my health?
Can I still get diphtheria if my test is negative?
How often should I get this test?
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 17, 2026. · Read our editorial policy