In Cohen and Boyer's pioneering studies of recombinant DNA, how did they know they had produced recombinant DNA?
A) They sequenced the DNA.
B) They cut the DNA with restriction enzymes.
C) They put the DNA fragments together with DNA ligase.
D) They had bacteria that were resistant to just one of the antibiotics.
E) They had bacteria that were resistant to both antibiotics.

Question

Quizplus · Accepted Answer

Cohen and Boyer used a plasmid that carried genes for resistance to two different antibiotics. By inserting foreign DNA into the plasmid using restriction enzymes and DNA ligase, only bacteria that had taken up the recombinant plasmid would be resistant to both antibiotics, indicating that recombinant DNA had been successfully produced.

In Cohen and Boyer's Pioneering Studies of Recombinant DNA, How