At the logarithmic stage of cell growth, add colchicine or colcemid to the culture medium for cell accumulation at the metaphase stage.

Nocadazole is also good for M-phase arrest.

Article Synchronization of HeLa Cells

Hi Goracle,

there are several methods to obtain enrichment of M phase Hela cells. all of the above mentioned methods work fine. Sometimes cells do not like it too much if they are incubated with these compounds over a longer period of time. some of the cells start to die, and this might interfere with your results. Additionally, you might use the CDK1 inhibitor Ro3306, which produces similar synchronization results. To my knowledge the simplest method to obtain G2/M phase cells is the mitotic shake off method. The method is described in the internet. It employs the round shape and lower attachment of cells in mitosis for collection. So, simply grow cells in a larger flask and tap it against something. Within the supernatant you should find cells in mitosis, which you can investigate further. You might repeat the procedure every hour or so to increase your yield.

Cheers

Axel