Sole-Specific IgG Radioallergosorbent (RAST) Test, Qualitative — Deprecated
A deprecated qualitative test for IgG antibodies against sole, a fish allergen. A positive result indicates exposure or sensitization but does not by itself confirm allergy.
["This older blood test can detect antibodies to sole, but its result alone cannot confirm or rule out an allergy."]
Key facts at a glance
- LOINC
- 21528-5
- Short code
- Deprecated Sole IgG RAST Ql
- Synonyms
- Deprecated Sole 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 blood test that looks for IgG antibodies directed against sole, a type of fish. RAST stands for radioallergosorbent test, a laboratory method used to detect allergen-specific antibodies. The test's LOINC entry is deprecated, so it may not be available or recommended by many laboratories.
Why might I need this test?
It may have been used to evaluate a possible reaction after eating sole or another fish. Because food-specific IgG testing does not reliably distinguish harmless exposure from clinical allergy, current allergy evaluation generally relies on the medical history, physical examination, and appropriately selected IgE-based testing.
How is the test performed?
A blood sample is analyzed in a laboratory to determine whether sole-specific IgG is present. The result is reported as positive or negative. Exact specimen requirements and testing availability should be confirmed with the performing laboratory because this test entry is deprecated.
How do I prepare for the test?
No special preparation is usually required for this type of blood test. Tell the clinician and laboratory if you have a known fish allergy, recent illness, or immune-system conditions, and follow any instructions provided for the test.
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 means that IgG antibodies to sole are detectable, which often reflects previous exposure and does not necessarily mean the person has a symptomatic allergy. A negative result does not completely exclude sole allergy. Results should be interpreted by a clinician alongside the symptoms and other appropriate allergy tests.
Short name
Sole IgG RAST
Frequently asked questions
Does a positive result mean I am allergic to sole?
Can I use this result to diagnose a food allergy?
Is this test still widely available?
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