Candida Antigen Immunoassay (Serum/Plasma)
This test detects the presence of Candida antigen in your blood, which may indicate an active fungal infection caused by yeast like *Candida*. It helps doctors assess if you have a systemic infection that requires medical evaluation.
["This test can help identify if you have a serious Candida infection that may need treatment beyond oral or topical therapies."]
Key facts at a glance
- LOINC
- 9501-8
- Short code
- CANDAG
- Synonyms
- Candida Ag Titr Ser
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube without anticoagulant
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Enzyme Immunoassay (EIA) / Immunodiffusion / Hemagglutination
- CPT
- 87449
- SNOMED
- 121921001
- Specimen volume
- 1-2 mL of serum (minimum 0.5 mL)
- Stability
- Stable at 2-8°C for 7 days; for longer storage, freeze at -20°C or below for up to 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 24–72 hours
- Order
- routine
What Is This Test Measuring?
The Candida antigen test looks for specific proteins (antigens) produced by *Candida* yeast in your blood. These antigens are released when the yeast is multiplying or causing tissue damage. The test is not specific to a particular *Candida* species but can signal an infection that may require antifungal treatment.
Why Might Your Doctor Order This Test?
Your doctor may recommend this test if you have symptoms like fever, persistent mouth or throat infections, or signs of a systemic infection (such as low blood pressure or confusion), especially if you have a weakened immune system, recent surgery, or are receiving long-term antibiotics.
Who Is at Higher Risk?
People at higher risk of *Candida* infections include those with weakened immune systems (e.g., from HIV/AIDS, chemotherapy, or organ transplants), individuals on long-term antibiotics, people with diabetes or other chronic illnesses, and those who have had recent surgeries or medical procedures.
What Does a Positive Result Mean?
A positive result means your blood contains Candida antigens, suggesting an active infection. However, it does not confirm the exact type of *Candida* or the severity of the infection. Your doctor will use this result along with clinical symptoms, physical exam, and possibly other tests to guide treatment.
Reference range
Titer < 1:4 (Negative); Titers ≥ 1:8 may suggest active or recent infection; results should be interpreted in conjunction with clinical findings and culture resultsN/A
No fasting required. Specimen should be collected prior to initiation of antifungal therapy when possible, as treatment may affect antibody/antigen titers.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Candida Ag Test
Frequently asked questions
How is this test performed?
What are the potential limitations of this test?
Will I need to prepare for 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 15, 2026. · Read our editorial policy