rates of collagen production per cell per unit time were quantitated by labeling hfl-1 with [ 14c ] proline and measuring the production of [ 14c ] hydroxyproline after taking into consideration the specific activity of [ 14c ] proline within the free intracelllular proline pool and the per cent hydroxylation of proline residues in newly synthesized collagen .
C0020388
hydroxyproline
C0033382
proline