Candida albicans antigen in serum or plasma (qualitative)
This test detects the presence of Candida albicans, a type of yeast commonly found in the mouth, gut, and other parts of the body. It helps identify infections caused by this fungus.
["The test checks for yeast infection signs in your blood or body fluids."]
Key facts at a glance
- LOINC
- 31758-6
- Short code
- CANDAG
- Synonyms
- C albicans Ag Ser Ql
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top vacutainer tube without anticoagulant
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Enzyme Immunoassay (EIA) or Immunofluorescence Assay (IFA)
- CPT
- 87449
- SNOMED
- 122593009
- Specimen volume
- 1.0-2.0 mL of serum (minimum 0.5 mL)
- Stability
- Stable at room temperature for 4 hours; refrigerated (2-8°C) for up to 7 days; frozen at -20°C or below for up to 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 50
- Icterus max
- 50
- TAT
- 24–72 hours
- Order
- routine
What This Test Measures
The Candida albicans antigen test looks for specific proteins (antigens) produced by the Candida albicans fungus. If Candida is present in your blood or body fluids, these antigens may be detected. This test is often used to diagnose systemic (whole-body) infections rather than localized ones, such as thrush in the mouth.
How the Test Works
The test uses an immunoassay method to identify the Candida albicans antigens. When you provide a blood or plasma sample, the lab analyzes it for these markers. A positive result suggests active infection, while a negative result means no detectable antigens were found.
When You Might Need This Test
Your doctor may recommend this test if you have symptoms like fever, fatigue, or unexplained infections, especially if you have a weakened immune system (e.g., from HIV, chemotherapy, or other conditions). It’s also used in patients with persistent fungal infections despite other treatments.
What the Results Mean
A positive result indicates the presence of Candida albicans antigens in your blood or body fluids, which may mean you have a systemic fungal infection. A negative result means no detectable antigens were found, but it doesn’t rule out infection entirely—other tests or samples may be needed for confirmation.
Reference range
Negative: No Candida albicans antigen detected. Positive: Candida albicans antigen detected, suggesting invasive candidiasis.N/A
No special patient preparation is required. Fasting is not necessary prior to specimen collection.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Systemic Candida infections can be serious, especially in people with weakened immune systems. Early detection helps guide treatment, such as antifungal medications, to prevent complications. This test is particularly useful for monitoring patients at higher risk, like those undergoing cancer treatment or with chronic illnesses.
Short name
Candida antigen test
Frequently asked questions
Why might my doctor order this test?
What does a positive result mean?
Can a negative result mean I don’t have an infection?
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