Cladosporium cladosporioides-Specific IgG Antibody, Qualitative (RAST)
A qualitative blood test for IgG antibodies to the mold Cladosporium cladosporioides, which may indicate previous exposure.
["A positive result suggests prior exposure to this mold but does not by itself confirm an active allergy."]
Key facts at a glance
- LOINC
- 26018-2
- Short code
- Deprecated C cladosporioides IgG RAST Ql
- Synonyms
- Deprecated C cladosporioides IgG RAST Ql
- Category
- liver
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84484
- SNOMED
- 302774002
- 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
What is this test?
This test looks for IgG antibodies to Cladosporium cladosporioides, a mold found in indoor and outdoor environments. The RAST designation refers to a laboratory allergy-antibody testing method. Because RAST is also commonly used for IgE testing, confirm with the ordering clinician that the report is specifically for IgG.
Why might I need this test?
It may be ordered when symptoms such as wheezing, nasal congestion, or skin irritation occur after exposure to mold or damp indoor environments. Testing can help evaluate whether the immune system has previously encountered this particular mold.
How is the test performed?
A blood sample is analyzed in the laboratory to detect antibodies to Cladosporium cladosporioides. The result is reported as positive, negative, or otherwise not detected, depending on the laboratory.
How do I prepare for the test?
No special preparation is usually required. Do not stop allergy medicines unless your clinician specifically instructs you to do so, because medications and active allergic symptoms may affect interpretation.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A positive IgG result generally indicates previous exposure to the mold and may reflect sensitization from the environment. It does not by itself prove that the mold is causing current symptoms or confirm an allergy. Clinical evaluation and, when appropriate, testing for mold-specific IgE or other causes of symptoms are needed for interpretation.
Short name
C. cladosporioides IgG (RAST)
Frequently asked questions
Does a positive result mean I am allergic to this mold?
What does a negative result mean?
Why is it important to confirm whether the test is IgG or IgE?
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