The splitting of 2-thiouracil by a pyrimidineless Escherichia coli.

Table 1. Concentration of thiouracil in the medium. In order to ascertain whether the decrease of radioactivity in the medium is accompanied by an incorporation into nucleic acids, these were separated in the following manner: the bacterial cells were washed twice and concentrated to 50 mg wet weight/ml. They were lysed by treating with sodiumdodecylsulfate (1%) and shaken with water-saturated phenol for fifteen minutes. The aqueous phase was removed and again extracted twice with water-saturated phenol.