Deprecated Sage-Specific IgG Antibody Radioallergosorbent Test (RAST), Qualitative
This legacy qualitative blood test looks for IgG antibodies directed against sage. It is not commonly used to diagnose sage allergy.
["A positive result shows sage-specific IgG antibodies but does not by itself confirm an allergy."]
Key facts at a glance
- LOINC
- 21507-9
- Short code
- Deprecated Sage IgG RAST Ql
- Synonyms
- Deprecated Sage 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 is a qualitative test for IgG antibodies that react with sage allergens. RAST stands for radioallergosorbent test, an older type of allergen-antibody testing. The test is marked as deprecated and may not be available at all laboratories.
Why might I need this test?
It may have been used to evaluate an immune response to sage, particularly in people reporting reactions after eating or preparing foods containing sage. Because it is an older test, a clinician may recommend more current allergy testing instead.
How is the test performed?
A blood sample is collected and analyzed in a laboratory for the presence of sage-specific IgG antibodies. The result is reported as positive, negative, or otherwise not detected.
How do I prepare for the test?
No special preparation is usually needed for this blood test. Tell your clinician about food allergies, recent reactions, and any immunosuppressive medicines, and follow the laboratory's specific instructions.
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 result indicates that sage-specific IgG antibodies are present, which may reflect prior exposure or sensitization. IgG antibodies are generally not used alone to diagnose a clinical food allergy, so symptoms and medical history must guide interpretation. Unexpected or severe reactions after sage exposure should be evaluated by an allergy professional.
Short name
Sage-specific IgG antibody test
Frequently asked questions
Does a positive result mean I am allergic to sage?
Why is this test described as deprecated?
What should I do if I have had a reaction to sage?
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.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy