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Rice-Specific IgG Antibodies, Qualitative — Radioallergosorbent Test (RAST) [Deprecated]

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

A qualitative blood test that detects antibodies directed against rice proteins. This test is deprecated and is not generally used to diagnose rice allergy.

Quick summary

["A positive result shows rice-specific IgG but does not by itself mean you have a rice allergy."]

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

Key facts at a glance

LOINC
21488-2
Short code
Deprecated Rice IgG RAST Ql
Synonyms
Deprecated Rice 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?

As encoded in the slug, this is a qualitative radioallergosorbent test (RAST) for rice-specific IgG antibodies. It is marked as deprecated, so it may not be available from most laboratories.

Why might I need this test?

This test may have been used to assess immune exposure to rice or help evaluate a suspected food-related reaction. However, food-specific IgG testing is not recommended as a routine method for diagnosing allergy.

How is the test performed?

A blood sample is collected, and the laboratory tests the serum for antibodies that bind to rice proteins. The result is reported as positive or negative rather than as a quantitative concentration.

How do I prepare for the test?

No special preparation is usually required. Tell the healthcare provider about food allergies, recent symptoms, and any immunosuppressive medicines, and follow the laboratory's collection instructions.

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

Rice IgG antibody test

Frequently asked questions

Does a positive rice IgG result mean I am allergic to rice?
No. Rice-specific IgG can occur in people who tolerate rice and is not considered a reliable marker of allergy. Your clinician should interpret the result alongside your symptoms and other allergy tests.
What is a RAST test?
RAST stands for radioallergosorbent test and is a laboratory method used to detect antibodies to specific allergens. The name is historical, and this rice IgG version is deprecated.
How is rice allergy usually evaluated?
A clinician usually considers the reaction history, timing of symptoms, and other tests such as food-specific IgE or skin-prick testing. An oral food challenge may be needed when the diagnosis remains uncertain.
  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