these results together with cell number determinations , autoradiography , and feulgen microspectrophotometry revealed three types of cells in these cultures : ( i ) 60 to 80 % of the cells replicated their dna once , divided , and then stopped mitotic activity , ( ii ) 5 to 10 % were going through a second round of dna replication ;
C0012854
dna
C0598312
dna