Fig. 1. Basophil activation test performed in whole blood. (A) Identification of basophil population in the lymphocyte-monocyte gate a SSC/CD203c+. (B) Flow cytometry dot plots of CD63 expression (%) on CD123+/HLA-DR-/CD203c+ cells. (C) Histogram showing the mean fluorescence intensity (MFI) median of CD203c expression. SI, stimulation index (ratio of stimulated/unstimulated basophils).