An analysis of changes in the expression of cyclins A and B1 by the cell array system during the cell cycle: Comparison between cell synchronization methods

Background A novel high‐throughput analysis, cell array system, was developed for an extensive study of the expression of genes and/or the degradation of gene products at the cellular level. To exemplify the usefulness of this system, we showed the changes in the expression level of cyclin A and B1 during the cell cycle in a single experiment. Methods We used the cell array system to chase the changes in cyclin A and B1 expression during the cell cycle in HeLa cells. Cells were synchronized by mitotic selection and thymidine‐hydroxyurea methods. Cells were harvested at intervals of 1 h from 0 through 23 h. These 48 cell samples were spotted on a circle of the cell array glass slide. Cyclin A and B1 were immunologically stained with Alexa Fluor 488, and nuclear DNA was stained with propidium iodide. The amount of cyclins and nuclear DNA were simultaneously measured by a laser scanning cytometer. Results Both cyclins were expressed in a cell cycle‐dependent manner as previously reported. The precise time‐course of the expression level of cyclins were obtained at a single experiment with this cell array system. Conclusions This study indicates that the cell array system is valuable to analyze temporal course of protein expression in relation to the cell cycle position and, that it facilitates antigen expression studies at the cellular level in multiple samples. Cytometry Part A 55A:24–29, 2003. © 2003 Wiley‐Liss, Inc.