hydroxyproline specific activity of nondialyzable procollagen in culture medium as well as extracellular and intracellular free proline specific activity were determined by an ultramicromethod in which the radiolabeled amino acids were reacted with [ 14c ] dansyl chloride of known specific activity [ airhart et al . ( 1979 ) anal . biochem . 96 , 45-55 ] .
C0020388
hydroxyproline
C0033382
proline