title: A direct selection method for isolating antimutators of Escherichia coli.
abstract: A screening procedure based on the formation of lactose-fermenting papillae on lactose-non-fermenting bacterial colonies has been described. Due to supplementation of 50 micrograms/ml 2-amino-purine in EMB plates the frequency of papillae rose to an average number of 28 papillae per colony. Of 150,000 mutagenized colonies inspected 16 colonies were detected with drastically reduced or no papillae per colony.
mesh_terms: D015075:2-Aminopurine / Q000494:pharmacology; D001431:Bacteriological Techniques; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005285:Fermentation; D005796:Genes; D007785:Lactose / Q000378:metabolism*; D009154:Mutation / Q000187:drug effects
chemical_list: D015075:2-Aminopurine; D007785:Lactose