A simple method for the assessment of the body sensitization has been developed, with peripheral blood neutrophils acting as the test system. The method consists in scintillation of the neutrophil count among the cells of the interphase ring obtained by centrifugation of 1:1 diluted peripheral blood in verografin density gradient, 1.077 g/cm3, after blood incubation with the tested allergen. Increase of the count of the neutrophils among other interphase cells by 20% or more after interaction with the allergen indicates a sensitization to this allergen. The accuracy and specificity of the method have been demonstrated in the examinations of patients with pollenosis and erysipelas.