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Brewer’s Yeast Basophil-Bound Antibody, Qualitative

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

A qualitative test that looks for antibodies directed against brewer’s yeast using a basophil-bound antibody assay.

Quick summary

["A detected result may indicate sensitization to brewer’s yeast but must be interpreted with your symptoms and medical history."]

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

Key facts at a glance

LOINC
7785-9
Short code
Brewer's yeast BasoBnd Ab Qn
Synonyms
Brewer's yeast BasoBnd Ab Qn
Category
liver
Sample
whole-blood
Container
Lavender-top (EDTA)
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
Method
lhr
CPT
84484
SNOMED
302774002
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

This test looks for antibodies that recognize brewer’s yeast, a yeast-derived ingredient used in some foods, beverages, supplements, and medicines. It is reported qualitatively, generally as detected or not detected.

Why might I need this test?

The test may be ordered if you develop hives, swelling, wheezing, digestive symptoms, or another reaction after consuming a product containing brewer’s yeast. It helps evaluate whether your immune system has developed a specific response to brewer’s yeast.

How is the test performed?

The laboratory uses a basophil-bound antibody testing approach to determine whether matching antibodies are present. Because this is a qualitative test, the result is generally reported as detected or not detected rather than as a specific concentration.

How do I prepare for the test?

No special preparation is identified by the abbreviated test name. Ask your clinician whether to avoid antihistamines before testing because these medicines can interfere with some basophil-based allergy tests; do not stop prescribed medication without guidance.

Reference range

Adult: 10-40 U/LN/A

Specimen: whole-blood

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

Brewer’s yeast antibody test

Frequently asked questions

What does a positive result mean?
It means that brewer’s yeast-directed antibodies were detected. This may support an allergic sensitization when the result matches your exposure history and symptoms.
Does a positive result diagnose a brewer’s yeast allergy?
Not by itself. Allergy generally requires compatible symptoms along with supporting test results and clinical evaluation.
Should I stop taking antihistamines before the test?
Ask your clinician first, because antihistamines can affect some basophil-based allergy tests. Continue prescribed medication unless your clinician specifically tells you to change it.
  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