Skip to content

Desert Ragweed-Specific IgE, Radioallergosorbent Test (RAST), Qualitative (Deprecated)

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

An older qualitative blood test that checks for IgE antibodies directed against desert ragweed pollen.

Quick summary

["A positive result indicates immune sensitization to desert ragweed, but it must be interpreted alongside allergy symptoms."]

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

Key facts at a glance

LOINC
15976-4
Short code
Deprecated Desert Ragweed IgE RAST Ql
Synonyms
Deprecated Desert Ragweed 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 blood test looks for IgE antibodies directed against desert ragweed pollen. IgE is a type of immune protein that can form in response to an allergen. The result is reported qualitatively, such as positive or negative.

Why might I need this test?

A clinician may order this test when allergy symptoms such as sneezing, runny nose, or itchy eyes occur around ragweed exposure. It can help identify whether the immune system recognizes desert ragweed as an allergen.

How is the test performed?

A blood sample is analyzed in the laboratory for antibodies that bind to desert ragweed allergen. Unlike a skin-prick test, this test does not directly expose your skin to the allergen.

How do I prepare for the test?

No special preparation is usually required for a blood-based IgE test. Because this test is marked as deprecated, check with the ordering clinician or laboratory to confirm that it is still the appropriate test and follow any instructions provided.

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

Desert ragweed-specific IgE

Frequently asked questions

What does a positive desert ragweed IgE result mean?
It means your immune system has produced IgE antibodies that recognize desert ragweed pollen. Your clinician will interpret this finding with your symptoms, exposure history, and other test results.
Does a positive result mean I will have allergy symptoms?
Not necessarily. The result indicates sensitization, while the timing and type of symptoms determine whether ragweed is likely causing your clinical symptoms.
Why is this test marked as deprecated?
It is an older testing method and has largely been replaced by newer laboratory assays. The ordering clinician can confirm whether an updated ragweed-specific IgE test is preferable.
  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