Test Principle ImmunoCAP Specific IgG4

The test technology is based on an extremely high total binding capacity, achieved through a high binding capacity per mg cellulose combined with an optimal quantity of cellulose in each solid phase. This ensures binding of all relevant antibodies, regardless of antibody affinity, while still giving low non-specific binding.

The ImmunoCAP solid phase consists of a cellulose derivative enclosed in a capsule. The hydrophilic, highly branched polymer provides an ideal microenvironment for allergens, binding them irreversibly while maintaining their native structure.

The test is designed as a sandwich immunoassay.

	The antigen of interest, covalently coupled to the solid phase, reacts with the specific IgG4 antibodies in the patient sample.
	After non-specific IgG4 antibodies have been washed away, enzyme-labelled antibodies against IgG4 are added to form a complex.
	After incubation, unbound enzyme-anti-IgG4 is washed away, and the bound complex is then incubated with a developing agent.
	After the reaction has been stopped, the fluorescence of the eluate is measured. The higher the fluorescence, the more specific IgG4 antibodies are present in the sample.