12.4 Each eukaryotic chromosome contains many replicons Figure 12. 9 Replication forks are organized into foci in the nucleus. Cells were labeled with BrdU The leftmost panel was stained with propidium iodide to identify bulk DNA. The right panel was stained using an antibody to brdu to identify replicating DNA 消当Figure 12.9 Replication forks are organized into foci in the nucleus. Cells were labeled with BrdU. The leftmost panel was stained with propidium iodide to identify bulk DNA. The right panel was stained using an antibody to BrdU to identify replicating DNA. 12.4 Each eukaryotic chromosome contains many replicons