Extended Data Figure 3. Cell cycle determination in nuclear donor cells.

a, Confluent fetal fibroblast (FF) populations subjected to flow cytometric processing. After sorting by size and density, 91% of small sized cells were in the G0/G1 phase of the cell cycle. b, Proliferating FF populations were mostly at S phase. c, ESC populations by flow cytometry. The size was correlated with the cell cycle, 70% of the small, medium and large size cell were at G0/G1, S and G2/M, respectively. d, FITC conjugated-BrdU was used to define S phase FFs and ESCs. e, Correlation of cell size and cell cycle in FFs and ESCs. Cell size was measured photographically after 3.7% formaldehyde fixation. S phase cells were separated by BrdU integration (green). The assignments of cell size provided in panels a, b and c were defined from the results in panel E (* p < 0.05), pFFs = proliferating fetal fibroblasts.