Figure 3From: Requirement of ATM-dependent pathway for the repair of a subset of DNA double strand breaks created by restriction endonucleasesClassification of the nuclei with foci. Synchronized normal human diploid cells in G1 were electroporated with Pvu II (100 U) as described in METHODS, and they were incubated for 2 hours before fixation. The nuclei were classified into 4 types. Type I; nuclei with diffused phosphorylated ATM signal, but without 53 BP1 foci. Type II; nuclei with numerous foci more than 30 foci. Type III; nuclei with countable foci below 30. Type IV; nuclei without detectable foci.Back to article page