title: F+ strains of Escherichia coli K-12 defective in Hfr formation.
mesh_terms: D000166:Acridines / Q000494:pharmacology; D002876:Chromosomes, Bacterial / Q000502:physiology; D003433:Crosses, Genetic; D004926:Escherichia coli / Q000187:drug effects; D005787:Gene Frequency; D011995:Recombination, Genetic; D013997:Time Factors; D014161:Transduction, Genetic
chemical_list: D000166:Acridines