in most experiments , chinese hamster ( line cho ) cells were synchronized in g1 , or they were synchronized in early s phase by allowing g1 cells to enter s phase in medium containing 1 mm hydroxyurea or 5 micrograms ml-1 aphidicolin , a procedure believed to produce an accumulation of initiated replicons that arise from normally early replicating dna .
C0007634
cells
C0080129
s phase