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Codfish-Specific IgE Antibody to rGad c 1, Qualitative (RAST)

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

A qualitative blood test that detects IgE antibodies to the recombinant codfish allergen rGad c 1, which may indicate a codfish allergy.

Quick summary

["A positive result suggests an immune response to codfish and may support evaluation for fish allergy."]

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

Key facts at a glance

LOINC
64037-5
Short code
Deprecated Codfish (rGad c) 1 IgE RAST Ql
Synonyms
Deprecated Codfish (rGad c) 1 IgE 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 detects IgE antibodies directed against rGad c 1, a recombinant form of parvalbumin, a major allergen found in codfish. It is sometimes described as a codfish-specific IgE RAST test.

Why might I need this test?

Your clinician may order it when a food allergy to fish or cod is suspected, especially after symptoms such as hives, swelling, wheezing, vomiting, or other reactions after eating cod.

How is the test performed?

A blood sample is tested in the laboratory to determine whether IgE antibodies to rGad c 1 are present. The result is reported as positive or negative, depending on whether the antibodies are detected.

How do I prepare for the test?

No special preparation is usually required for this blood test. Follow the instructions provided by your healthcare professional or laboratory, and tell the clinician if you have a known fish allergy or recently had an allergic reaction.

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

Codfish rGad c 1 IgE

Frequently asked questions

What does a positive result mean?
It means your blood contains IgE antibodies to rGad c 1, a codfish allergen. This supports an allergic sensitization to codfish and should be reviewed with your clinician.
Does a positive result mean I will have an allergic reaction?
Not necessarily. IgE antibodies can be present without symptoms, so the result should be interpreted alongside your reaction history and other clinical findings.
Can this test diagnose fish allergy?
It can provide important evidence of sensitization to codfish, but it does not stand alone. Your clinician may also consider your symptoms, other food allergy tests, and sometimes a supervised food challenge.
  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