Principles of the test procedure

The allergen components are spotted in triplets and covalently immobilized on a polymer coated slide. Each slide contains 4 microarrays giving results for 4 different samples per slide.

ImmunoCAP ISAC is a two-step assay:

  1. IgE antibodies from the patient sample bind to the immobilized allergen components.
  2. Allergen-bound IgE antibodies are detected by a fluorescence labeled anti-IgE antibody.

The test procedure (including washing and incubation steps) gives a total assay time of less than 4 hours.

Fluorescence is measured with a laser scanner and results are evaluated using Phadia Microarray Image Analysis (MIA) software. The MIA SW has a user-friendly interface and enables automatic readout and customized result reports.

ImmunoCAP ISAC is a semi-quantitative test and results are reported in ISAC Standardized Units (ISU) giving indications of specific IgE antibody levels within a measuring range of 0.3 – 100 ISU-E. The ISU-E are standardized to ImmunoCAP Specific IgE units.


As in all diagnostic testing, the diagnosis is made by the physican based on both test results and the patient history.