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Oxford University Hospitals NHS Foundation Trust

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Allergy: Specific IgE antibodies

Also known as: RAST; Allergen Testing; SIgE

Specific IgE tests are available to a wide range of antigens. However, the Gold Standard is a thorough clinical history along with skin prick tests except in the following cases:

  • Small children
  • Those with extensive skin involvement that precludes skin testing
  • Where there is a risk of anaphylaxis

In the absence of a strong clinical history, Specific IgE analysis is of little significance.

Blanket requests for 'RAST testing' will be ignored.

Please give full details of suspected allergens and symptoms. Tests for specific IgE to penicillin are not reliable in diagnosing immediate type hypersensitivity to this drug.

For further information on Food Allergy in children and young people, please see the latest NICE Guidelines from February 2011 (CG116):

View a list of available antigens

Specimen requirements

Serum or plasma - 2ml


Price on application

Laboratory turnaround time

3 days

Laboratory method

Immunocap automated Enzyme Immunoassay

Reference range/units

Reported as Grades Units (Ku/l) Interpretation
0 - 0.35 Negative
0.35 - 0.7 Weakly positive
0.7 - 3.5  
3.5 - 17.5  
17.5 - 50  
50 - 100  
>100 Strongly positive

Associated tests

Not applicable

Shipping and storage

UK and Ireland

Ambient temperature and first class post. Hays DX users please enquire via email below.


Ambient temperature if courier will deliver within 72 hours otherwise consider refrigerated transport. Freezing is not a requirement.

Ensure delivery Monday to Friday 07:00 - 17:30.

Further information and contact details

For further information, email