many factors affect the uptake of this agent into newly synthesized dna : predominance of denovo and salvage pathways of thymidilate biosynthesis , activity of certain enzymes , size of thymidilate and ttp endogenous pools , differences in 3h-thymidine utilization rate during s-period , its catabolism in cell and tissue culture systems , degradation by bacteria , its reutilization in vivo and in vitro , effects of the isotope activity , of the exposition time of autoradiographs and of the beta-particles absorbance in the specimen .
C0080129
s-period
C0007634
cell