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Wheat Bran-Specific IgG Antibody Test, Qualitative (RAST) — Deprecated

Published: August 9, 2026Updated: August 17, 2026

A blood test that looks for IgG antibodies to wheat bran. This deprecated test indicates prior exposure but does not by itself diagnose wheat allergy.

Quick summary

["A positive result usually reflects exposure or sensitization to wheat rather than proving a symptomatic wheat allergy."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
25355-9
Short code
Deprecated Wheat Bran IgG RAST Ql
Synonyms
Deprecated Wheat Bran 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 checks a blood sample for IgG antibodies directed against wheat bran, a component of wheat. It is reported as a qualitative result and is considered deprecated.

Why might I need this test?

It may have been used to evaluate a suspected food-related reaction or document immune sensitization to wheat. A clinician must interpret it alongside symptoms, diet, and other allergy testing.

How is the test performed?

A blood sample is tested for wheat bran-specific IgG antibodies using a qualitative laboratory method. No home collection is required.

How do I prepare for the test?

No special preparation is generally required. Follow any instructions from your clinician, and do not stop eating wheat or begin an elimination diet solely for this test unless advised.

Reference range

Adult: 10-40 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Wheat bran IgG antibody test

Frequently asked questions

Does a positive wheat bran IgG result mean I am allergic to wheat?
No. A positive result shows detectable wheat bran-specific IgG and may reflect prior exposure or sensitization, but it does not by itself diagnose a symptomatic allergy.
Why is this test called deprecated?
It is no longer a preferred test for diagnosing food allergy. Current evaluation is more likely to rely on your history, physical examination, and targeted IgE or other testing when clinically appropriate.
Can I stop eating wheat before this test?
Do not eliminate wheat unless your clinician recommends it. Changes in wheat intake and other factors can affect interpretation, so follow the instructions provided with the test order.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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