BiocHEMicM. i>kopi:ktii:s of tuk isolatkd nucleus 



197 



Control' nuclei 



DNAose- treated nuclei 



Ml. effluent 



Fig. 5. Chromatographic separation of ATP from other nucleotides in extracts of isolatcil 

 ceil nuclei. The optical density of the effluent, E-go, is plottcti against the volume of solution 

 passing through a column of Dowex-i (formate). Curve A shows the pattern obtained from 

 an acid extract of untreated thymus nuclei. Ciine B shows the corresponding pattern obtained 

 from nuclei pretreated with deoxyribonucleasc. Note the decrease in the ATP peak. Ctirves C 

 and D show the result of adding supplements of thymus DNA and yeast RNA to the DN.Aase- 

 treated nuclei. The magnitude of the increase in .^TP synthesis under these conditions is given 

 in table 6. 



