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Tuna-Specific IgG Antibody (RAST), Qualitative — Deprecated

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

A qualitative blood test that detects IgG antibodies directed against tuna. This legacy test does not by itself confirm a clinical tuna allergy.

Quick summary

["A positive result shows tuna-specific IgG antibodies but does not necessarily mean you have a tuna allergy."]

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

Key facts at a glance

LOINC
19047-0
Short code
Deprecated Tuna IgG RAST Ql
Synonyms
Deprecated Tuna 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 uses the radioallergosorbent test (RAST) method to look for IgG antibodies against tuna in a blood sample. It reports the result as positive or negative and is considered a deprecated or legacy test.

Why might I need this test?

It may have been ordered to evaluate a suspected food-related reaction to tuna or to show prior immune exposure to tuna. Food-specific IgG testing generally does not establish whether a food causes symptoms.

How is the test performed?

A blood sample is collected and tested in the laboratory for antibodies that bind to tuna antigens. The result is reported qualitatively as positive or negative.

How do I prepare for the test?

No special preparation is usually required. Follow any instructions from your clinician or testing laboratory, and tell the laboratory if you have recently taken a medicine that could affect immune test results.

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

Tuna IgG RAST

Frequently asked questions

Does a positive result mean I am allergic to tuna?
No. Tuna-specific IgG antibodies can occur in people without clinical allergy, so symptoms and medical history must guide interpretation.
What should I do if I have symptoms after eating tuna?
Discuss the reaction with your clinician. Severe symptoms such as trouble breathing, throat swelling, faintness, or widespread hives require urgent medical attention.
Why is this test marked as deprecated?
It is a legacy testing method, and food-specific IgG results are not generally used to diagnose food allergy. Your clinician can select a more appropriate evaluation based on your symptoms.
  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