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Ascorbate Oxidase-Specific IgE, Qualitative (Deprecated)

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

A qualitative allergy test that checks for IgE antibodies directed against ascorbate oxidase, a plant enzyme that may act as a food allergen.

Quick summary

["A positive result suggests sensitization to ascorbate oxidase but must be interpreted with allergy symptoms and other testing."]

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

Key facts at a glance

LOINC
91666-8
Short code
Deprecated Ascorbate oxidase IgE RAST Ql
Synonyms
Deprecated Ascorbate oxidase 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 ascorbate oxidase, a plant enzyme that can act as a food allergen. It is reported qualitatively, generally as detected or not detected.

Why might I need this test?

It may be used to evaluate possible sensitization to foods containing ascorbate oxidase, especially after a suspected reaction. Results are considered together with your symptoms, exposure history, and other allergy tests.

How is the test performed?

This type of allergy test is generally performed using serum from a blood sample. The laboratory checks for allergen-specific IgE and provides a qualitative result rather than a measured concentration.

How do I prepare for the test?

Fasting is usually not required for this test. Follow your clinician's instructions, and do not stop prescribed antihistamines or other medicines without discussing it with the ordering clinician.

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

Ascorbate Oxidase IgE

Frequently asked questions

Does a positive result mean I have an ascorbate oxidase allergy?
Not necessarily. It indicates sensitization, and your clinician must interpret it alongside your symptoms, food exposure, and other allergy evidence.
Can a negative result rule out this allergy?
No. Some allergic reactions may occur without detectable IgE, so a negative result does not completely exclude an allergy.
Why is this test marked as deprecated?
Deprecated means the test code may no longer be routinely offered or may have been replaced by another laboratory method. Ask the ordering clinician about the current testing option available.
  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