When the bacteriophages infected the bacteria , the progeny contained the radioactive isotopes in their structures .
Hershey and Chase inserted the radioactive elements in the bacteriophages by adding the isotopes to separate media within which bacteria were allowed to grow for 4 hours before bacteriophage introduction .
When the bacteriophages infected the bacteria , the progeny contained the radioactive isotopes in Hershey 's structures .
Hershey and Chase inserted the radioactive elements in the bacteriophages by adding the isotopes to separate media within which bacteria were allowed to grow for 4 hours before bacteriophage introduction .