1.Previous
3.Next

as the time between mitosis and S phase. No molecular or morphological place-markers for a cell's position in G₁ were known. Pardee used a double-block method in which he shifted cells from one cell cycle block (such as critical amino acid withdrawal or serum withdrawal) to another and compared each block's efficiency at preventing progression to S phase. He found that both blocks in all cases examined were equally efficient at blocking S phase progression, indicating that they must all act at the same

1.Previous
3.Next