Deprecated Cottonseed-Specific IgG Antibody, Radioallergosorbent Test (RAST), Qualitative
A deprecated qualitative blood test for detecting cottonseed-specific IgG antibodies. It is not commonly used for diagnosing food allergy.
["This historical test can show whether IgG antibodies to cottonseed are present, but a positive result does not by itself diagnose an allergy."]
Key facts at a glance
- LOINC
- 21228-2
- Short code
- Deprecated Cottonseed IgG RAST Ql
- Synonyms
- Deprecated Cottonseed 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 radioallergosorbent test (RAST) that looks for IgG antibodies directed against cottonseed proteins. The result is qualitative, meaning it reports whether antibodies were detected. The test has been deprecated and is not generally used in current allergy practice.
Why might I need this test?
It may have been used historically to evaluate a suspected immune response to cottonseed, particularly in people with symptoms after eating cottonseed or products containing it. Because it is deprecated, a current clinician may instead recommend a more specific allergy evaluation, such as skin-prick testing or food-specific IgE testing when appropriate.
How is the test performed?
A blood sample is analyzed in the laboratory using the RAST method, in which the sample is exposed to cottonseed allergen and antibodies are measured. The final report is qualitative rather than a numerical measurement.
How do I prepare for the test?
No special preparation is usually associated with this test, but instructions from the ordering clinician or laboratory should be followed. Do not stop medications or avoid suspected foods without medical advice, particularly if you have had a serious allergic reaction.
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 detectable result indicates that cottonseed-specific IgG antibodies are present. IgG antibodies can reflect prior exposure or tolerance and do not, by themselves, establish a clinically significant cottonseed allergy. Because this test is deprecated, any result should be interpreted alongside symptoms, exposure history, and more specific allergy testing.
Short name
Cottonseed IgG antibody test
Frequently asked questions
Does a positive cottonseed IgG result mean I am allergic to cottonseed?
Why has this test been deprecated?
What should I do if I have reacted to cottonseed?
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