Results The data of Table I show that g~ anine-8-C'~ was utilized to the same extent for all the purines of the various fractions, within the accuracy of the method. It is evident that T. geleii W. utilizes exogenous purine exclusively, and does not synthesize purine from smaller precursors; such synthesis would dilute the activity of the guanine administered. As further evidence for lack of synthesis, no activity was found in ASN purines, total nucleic acids or ...
