Abnormal neutrophil morphology and association with increased microfilaments. (A) Neutrophils from a normal subject (top row) and patient I.2.3 (middle row) were stained for F-actin (Alex Fluor 546 phalloidin), and the nuclei were stained with 4',6-diamidino-2-phenylindole. Fluorescence and differential interference contrast images are shown individually and merged. Neutrophils with herniated nuclear lobes are indicated by white arrows in the phalloidin-stained and merged images of patient I.2.3. A higher magnification (×1000) of neutrophils from patient I.2.3 is presented in the bottom row. (B) Neutrophil flow cytometric phalloidin staining. Unstained cells are shown in gray outline, whereas F-actin–containing cells labeled with Alex Fluor 546 phalloidin are shown in solid dark.