Fig. 7. Caffeine did not affect focus-formation of RPA. Demembranated Xenopus sperm nuclei were incubated in the extract containing 5 mM caffeine for 60 minutes at 23°C in the presence of EcoRI (A) or CPT (B). Localization of RPA (a,c) and DNA (b) is shown. Panel c is an enlarged image of the nucleus indicated by an arrowhead in panel a. The same nucleus is also indicated by an arrowhead in panel b. Bars, 50 µm (a,b) or 20 µm (c).