Eosinophils display cytoplasmic and cell membrane-staining patterns for SCF.

(A) Representative eosinophils with the Texas red channel corresponding to SCF (i), the FITC channel corresponding to MBP (ii), and combined fluorescence (iii). (B) Representative eosinophils with the Texas red channel corresponding to SCF (i), the FITC channel corresponding to c-Kit (ii), and combined fluorescence (iii). Isotype controls displayed minimal fluorescence background after subtraction of autofluorescence (Aiv and Biv). Original magnification, ×63. Control cells consisted of foreskin fibroblasts and HMC-1. Foreskin fibroblasts showed an intense membranal staining of SCF and were negative for c-Kit, whereas HMC-1 displayed intense membrane staining and weak, diffuse cytoplasmic staining for SCF that did not colocalize with the c-Kit receptors (not shown).