###1: Soybean rGly m 4-Specific IgE Antibody, Qualitative (RAST)
###3: This blood test checks for IgE antibodies directed against rGly m 4, a component of soybean. A positive result indicates sensitization to this soybean component but does not by itself confirm a clinical soybean allergy.
["###4: A positive result suggests soybean sensitization and should be interpreted alongside symptoms and other allergy testing."]
Key facts at a glance
- LOINC
- 81983-9
- Short code
- Deprecated Soybean (rGly m) 4 IgE RAST Ql
- Synonyms
- Deprecated Soybean (rGly m) 4 IgE RAST Ql
- Category
- glucose
- 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
###5: What the test measures
###6: The test detects IgE antibodies to the recombinant soybean allergen component rGly m 4. Because the result is qualitative, it is reported as positive or negative rather than with a numerical concentration.
###7: How the test is used
###8: This is a blood-based allergy test that may help identify whether soybean-related symptoms are associated with an IgE-mediated response. Results are commonly considered with the food history, symptoms, and other tests for soybean allergy.
###9: Understanding a positive result
###10: A positive result means the immune system has produced IgE antibodies against rGly m 4. This supports sensitization but may occur in people who tolerate soybean or have never experienced a reaction to it.
###11: Test availability
###11: This component-specific RAST test is deprecated and may no longer be available for routine ordering. An allergist can advise on current food-allergy testing options if soybean allergy is suspected.
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.
###13: Clinical significance: A positive result can help explain reactions such as hives, swelling, wheezing, or gastrointestinal symptoms occurring after soybean exposure, but it cannot establish which symptoms are caused by soybean. A negative result lowers the likelihood of IgE-mediated allergy to rGly m 4 but does not rule out every type of food reaction. Decisions about food avoidance, food challenges, or emergency medication should be made with a qualified healthcare professional.
Short name
###2: Soybean component IgE (RAST)
Frequently asked questions
###14: Does a positive result mean I am allergic to soybean?
###16: Can I still eat soybean if the result is positive?
###18: What if the result is negative?
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