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Fish Feed-Specific IgE (RAST), Qualitative — Deprecated

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

A qualitative blood test that looks for IgE antibodies to fish-feed proteins. The test is marked deprecated and may need to be replaced with another allergy test.

Quick summary

["A positive result suggests sensitization to fish-feed proteins but must be interpreted alongside symptoms and exposure history."]

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

Key facts at a glance

LOINC
19044-7
Short code
Deprecated Fish Feed IgE RAST Ql
Synonyms
Deprecated Fish Feed 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 looks for IgE antibodies directed against proteins in a fish-feed preparation. A RAST-type laboratory method combines the patient's sample with the allergen to determine whether specific IgE is present.

Why might I need this test?

It may be considered when a person has symptoms associated with exposure to fish feed, such as hives, wheezing, swelling, or other allergic reactions. Because this test is deprecated, the laboratory or clinician may recommend a newer allergy test instead.

How is the test performed?

A blood sample is collected and tested in the laboratory against the fish-feed allergen. This qualitative test reports whether reactive antibodies are detected rather than providing a numerical IgE concentration.

How do I prepare for the test?

No special preparation is usually required for a blood draw. Tell your clinician about the type of fish-feed exposure, any allergic symptoms, relevant medical conditions, and medicines or supplements you are taking; do not stop medications without 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

Fish feed-specific IgE

Frequently asked questions

Does a positive result mean I am allergic to fish feed?
Not necessarily. It shows that specific IgE antibodies were detected, so the result must be compared with your symptoms and actual exposure history.
Can I eat fish if this test is positive?
This result does not by itself determine whether eating fish is safe. Ask your clinician or allergist whether the result is relevant to fish ingestion or only to exposure to fish-feed proteins.
Why is this test marked deprecated?
A deprecated test is no longer the preferred or most reliable choice for the intended clinical question. Your clinician may order a newer specific-IgE test or another allergy evaluation.
  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