single-strand specific digestion with nuclease s1 of nuclear lysates from ultraviolet-irradiated cells , pulse labelled in the presence of hydroxyurea/arabinosylcytosine , caused a release of about 70 % of the prelabelled dna and 90 % of the pulse-labelled dna from the rapidly sedimenting material in sucrose gradients .
C0000702
a
C0012854
dna