Figure 1.

“Baby machine”–based cell cycle synchronization. (A) Schematic representation of the retroactive synchronization method. The cell cycle phases are represented by the bars on the top and right side of the figure. The eight samples collected by the “baby machine” are shown along with the time they were collected (the time after the end of the BrdU labeling is shown). The position and the pattern of the horizontal bars on the left of each sample, represents the portion of S that was BrdU-labeled in each sample. (B) BrdU containing DNA immunoprecipitated from each sample was subjected to semi-quantitative PCR. PCR products were detected for mouse mitochondrial DNA (MITO), demonstrating the uniform loading of newly replicated DNA (Buzina et al. 2005). On the other hand, the early replicating gene (Actb) is enriched in the early samples and the late replicating regions (Hbb and X141) in late samples.