Weed Allergen Mix 2-Specific IgE, Serum — Radioallergosorbent (RAST) Test
A blood test that measures IgE antibodies to a panel of weed allergens to help identify possible weed-related allergy sensitization.
["A positive result suggests an immune reaction to one or more tested weed allergens, but it must be interpreted alongside your symptoms and exposure history."]
Key facts at a glance
- LOINC
- 24494-7
- Short code
- Weed Allerg Mix2 IgE RAST
- Synonyms
- Weed Allerg Mix2 IgE RAST
- 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
- Method
- multidisk
- 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 measures weed-specific IgE antibodies in your blood. IgE is an immune-system protein that can form in response to exposure to a particular allergen.
Why might I need this test?
Your clinician may order it to evaluate possible allergy symptoms such as sneezing, runny nose, itchy or watery eyes, wheezing, or hives, especially when symptoms occur near weeds.
How is the test performed?
A blood sample is collected and tested in a laboratory using a radioallergosorbent or similar immunoassay method. The laboratory measures IgE directed against the allergens included in weed mix 2.
How do I prepare for the test?
This test usually requires no special preparation. Tell your clinician about any medicines you take, because antihistamines and certain other treatments may affect allergy-test results; do not stop them without medical advice.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Detectable or elevated results suggest sensitization to one or more weed allergens in the panel. This does not by itself confirm that the allergens are causing your symptoms, so results should be compared with your medical history, timing of exposure, and examination. Undetectable or very low results make IgE-mediated allergy to the tested weeds less likely.
Short name
Weed Allergen Mix 2 IgE
Frequently asked questions
Does a positive result mean I am allergic to weeds?
Can this test show which weed caused my symptoms?
Should I stop taking allergy medicine before the test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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