a reversible growth arrest of simian virus 40-transformed human fibroblasts has been produced by replacement of methionine in the growth medium by its immediate metabolic precursor , homocysteine , although these arrested cells exhibit a greatly reduced cloning efficiency when plated in methionine-supplemented medium , they resume rapid proliferation without a lag when subconfluent cells are refed with methionine-supplemented medium .
C0016030
fibroblasts
C0007634
cells