A multi-laboratory evaluation of a clinically-validated incurred quality control material for analysis of allergens in food.

A dessert matrix previously used for diagnosis of food allergies was incurred with pasteurised egg white or skimmed milk powder at 3, 6, 15 and 30 mg allergen protein per kg of dessert matrix and evaluated as a quality control material for allergen analysis in a multi-laboratory trial. Analysis was performed by immunoassay using five kits each for egg and milk (based on casein) and six 'other' milk kits (five based on β-lactoglobulin and one total milk). All kits detected allergen protein at the 3 mg kg(-1) level. Based on ISO criteria only one egg kit accurately determined egg protein at 3 mg kg(-1) (p=0.62) and one milk (casein) kit accurately determined milk at 6 (p=0.54) and 15 mg kg(-1) (p=0.83), against the target value. The milk "other" kits performed least well of all the kits assessed, giving the least precise analyses. The incurred dessert material had the characteristics required for a quality control material for allergen analysis.