F-actin re-distribution in response to challenge with anti-CD24 antibody. Showing representative confocal optical slice images. (A) Cultures prepared 3 h after challenged with isotype control antibody. Showing variable profile from phalloidin staining. Some cells show typical F-actin filaments extending along the long axis of the cell. Others show clustering of F-actin to cell borders in regions of close intercellular contact. (B) Cultures prepared 3 h after challenged with anti-CD24 antibody. The majority of cells show intense staining for F-actin that is peripherally localized to cell borders. Bars, 20 μm.