Fig. 3. Double immunostaining of FAK and phosphotyrosine. All images were acquired and processed as in Fig. 1. Note that FAK levels in small adhesions have already increased at 3 minutes, whereas PY levels remain almost unchanged. Both FAK and PY reach their maximal levels at 10 minutes, remain high for up to 30 minutes, and return to control levels by 60 minutes. Bar, 1 µm.