Crosslinking of various cell-surface molecules by MoAbs. (A) Western blot of Triton X-100 lysates of KG1a cells stimulated for 30 minutes with anti-CD34 (4A1), anti-CD11a, anti-CD18, anti-CD49d, anti-CD49e, or anti-CD54 as described in the legend to Fig1. Molecular size markers are indicated on the left (kD). (B) Distribution of adhesion molecules on KG1a cells stimulated as described above. After fixation, cells were double-stained with FITC–anti-mouse Ig (green channel: b, f, j, n, and r) and phalloidin (red channel: c, g, k, o, and s), and analyzed by Nomarski differential-interference-contrast (left-hand panels) and confocal immunofluorescence microscopy. The right-hand panels show superimposed images of green and red channels. Bars, 10 μm.