Human eosinophil detected in a buffy coat cytospin. (A) The eosinophil was stained specifically with mouse monoclonal anti-human RANTES (20 μg/mL) using APAAP staining, as indicated by the arrow. Two unlabeled cells are also visible within this field, a neutrophil possessing a multilobed nucleus (upper left) and a lymphocyte (left of the stained eosinophil). (B) Isotype control using mouse IgG1 antibody (20 μg/mL). Original magnification × 100.