Candida Antigen (Serum) – Quantitative
This test measures the presence of fungal antigens from *Candida* species in your blood, which can help detect active infections like candidiasis.
["This test helps identify if you have a serious fungal blood infection that may require treatment."]
Key facts at a glance
- LOINC
- 16539-9
- Short code
- CANDAG
- Synonyms
- Candida Ag Ser Ql
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top vacutainer tube; alternatively, a sterile serum collection tube without anticoagulant
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Enzyme Immunoassay (EIA) / Lateral Flow Immunoassay for detection of Candida species antigen (mannan and/or beta-D-glucan) in serum
- CPT
- 87449
- SNOMED
- 122446006
- Specimen volume
- 1.0–2.0 mL of serum (minimum 0.5 mL)
- Stability
- Serum stable for 24 hours at room temperature (20–25°C); up to 7 days at 2–8°C; up to 30 days at -20°C or below for prolonged storage. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 4–24 hours
- Order
- routine
What Does This Test Measure?
The test looks for specific antigens produced by *Candida* fungi in your serum. These antigens are released when the fungus is actively multiplying in your bloodstream, which can indicate an infection beyond the mouth or skin.
Why Might Your Doctor Order This Test?
Your doctor may recommend this test if you have symptoms like fever, fatigue, or unusual infections that don’t improve with typical antibiotics, especially if you have weakened immunity (e.g., from chemotherapy, diabetes, or HIV). It’s also used in patients with central venous catheters or those undergoing long-term broad-spectrum antibiotic use.
How Is the Test Performed?
A blood sample is drawn from a vein, typically in your arm. The serum (liquid part of blood) is then tested for the presence of *Candida* antigens using a sensitive immunoassay method.
What Are Possible Results?
A positive result indicates the presence of *Candida* antigens in your blood, suggesting an active infection. A negative result means no detectable antigens were found, but this doesn’t always rule out infection—other tests or cultures may be needed.
Reference range
Negative (No Candida antigen detected). Positive results indicate the presence of circulating Candida antigen, suggestive of invasive candidiasis or systemic candidal infection.N/A
No special patient preparation required. Fasting is not necessary. Specimen should be collected prior to initiation of antifungal therapy when possible, as antifungal treatment may reduce antigen levels and yield false-negative results.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is critical for diagnosing invasive candidiasis, a rare but serious fungal infection that can affect organs like the lungs, heart, or brain. Early detection helps guide treatment with antifungal medications, which can prevent life-threatening complications. It’s especially useful in high-risk patients where symptoms may be subtle or non-specific.
Short name
Candida Antigen Blood Test
Frequently asked questions
How long does it take to get results from this test?
Can this test be done at home?
What if my test result is positive?
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