Alternative name: RAST
Description: The presence of significant levels of specific IgE antibodies to defined allergens in conjunction with a relevant clinical history is suggestive of IgE mediated allergy. IgE antibodies to over 1000 different allergens can be measured.For allergy testing. Request must specify which allergens should be tested based on clinical history.The laboratory is happy to suggest appropriate testing. Please provide as much clinical information as possible.
Indication: Identification of IgE to allergens responsible for allergic disorders.
Interpretation: See Allergy testing General Information
Sample: Serum Separator Tube (SST)
Assay details: Fluorescence enzyme linked immunoassay (Phadia Immunocap 250).
Restrictions: Less frequently requested allergens are referred to Supraregional PRU and Department of Immunology, Sheffield
Reference range:
Assay range notes: Results are expressed in terms of a grade or as a serum concentration of specific IgE

  • Grade 0 = <0.35KUA/L (negative)
  • Grade 1 = 0.35-0.7KUA/L (weak positive)
  • Grade 2 = 0.7-3.5KUA/L (positive)
  • Grade 3 = 3.5-17.5KUA/L (positive)
  • Grade 4 = 17.5-52.5KUA/L (strong positive)
  • Grade 5 = 52.5-100KUA/L (strong positive)
  • Grade 6 = >100KUA/L (strong positive)Note Units are arbitarily related to total IgE international reference concentration)
Turnaround time: 5 – 7 Days for in house testing, up to 28 days for referred testing.
Analysing laboratory: Immunology, The James Cook University Hospital