Immunoassay

The invention provides a method of quantifying multiple antigen-specific immunoglobulins in a test sample, the method comprising utilising a serial dilution of anti-immunoglobulin antibodies, fragments or derivatives thereof, immobilised on a solid support in combination with a serial dilution of a reference sample of immunoglobulin to generate multiple binding capacity curves. Such binding capacity curves are matched to specific dose response curves generated for each specific antigen to be tested using serum samples of known reactivity to those antigens to provide a calibration system that enables more accurate analysis of antigen-specific immunoglobulin in a sample. The invention also provides methods for calibrating a device suitable for assaying multiple antigen-specific immunoglobulins binding to multiple antigens or fragments thereof immobilised on a solid support. A multi-allergen test system and kits for use in the methods are also provided.