If you have FACS if not RT-PCR of cyclines specified for each step of cell cycle

If you have FACS do PI staining if not RT=PCR for cyclines and CDKIs

thank you.. in case of RT-PCR of cyclines ..you mean analysing the checking points in which the cells pass from one phase to another ? and if so ..threre will bw any specefic changes?

Yes, an increase and/or decrease in cyclines may indirectly suggest to the cycle the cells are but the best method is FACS.