AN IMPROVED METHOD OF CELL-CYCLE SYNCHRONIZATION FOR THE HETEROTROPHIC DINOFLAGELLATE CRYPTHECODINIUM-COHNII BIECHELER ANALYZED BY FLOW-CYTOMETRY

The selective attachment method for synchronising populations of Crypo thecodinium cohnii Biecheler has been investigated with the addition o f a filtration step. Appropiate tilter meshes can yield populations en riched with cells at a similar point in the G1 phase of the cell cycle , the degree of synchrony being 90-93% G1 cells. Flow cytometric analy sis of DNA content allowed the cell cycle progression of synchronised cells to be followed after the synchronisation event. Results indicate that the additional filtration step did not physiologically affect th e cells and the calculated cell-cycle phase duration results are consi stent with other published data. The technique has been demonstrated o n a scale which would be suitable to provide the large samples require d for molecular biology studies such as cell-cycle control.