Fig. 1.

Identification of resting and activated basophils from peripheral blood by flow cytometry. All leukocytes were stained with CD3, CD294, and CD203c. All leukocytes formed discrete FSC/SSC populations after fixation and lysis (a). CD3-positive events (R1) were removed due to the isolation of lymphocytes and monocytes (b). Basophils were defined as CD294 (CRTH2)-positive events (R2) (c). CD203c is a specific marker of activated basophils. Line A was drawn so that 2–5% of basophils were included above it, and we defined them as activated basophils. We compared the percentage of basophils above line A before and after the stimulation (d). These experiments were performed using the Allergenicity Kit (Beckman Coulter Company, Brea, CA, USA)