Abstract: A method for the measurement of the activation of the basophils following stimulation with an allergen to determine hypersensitivity to some substances, in which a blood sample with an addition of interleukin-3 in a quantity of 0.05 to 50 ng/ml based on the volume of the sample, and of appropriately diluted allergen in a quantity of 0.5 to 100 units/ml is incubated at the temperature corresponding to the physiological environment for 15 to 45 minutes, whereafter a staining with anti-CD63.antibody in an amount of 3 to 30 &mgr;l/100 &mgr;l of blood and with the antibody against a receptor of the basophil in an amount of 3 to 30 &mgr;l/100 &mgr;l of blood are added at a temperature of 0 to +10° C. and the sample, after vortexing, is then incubated in an ice bath for 15 to 30 minutes, and then is lysed and subjected to flow cytometry.