Biology 2nd Edition by Robert Brooker, Eric Widmaier ,Linda Graham ,Peter Stiling

Exercise 14

Let's suppose you followed the protocols described in FigureS₂0.2 and 20.3. Which experiment(s) would you conduct to confirm that a white colony really contained a recombinant vector with an inserted fragment of DNA
A) Pick a bacterial colony and restreak on plates containing X-Gal to confirm that the cells really form white colonies.
B) Pick a bacterial colony, isolate plasmid DNA, digest the plasmid DNA with a restriction enzyme, and then perform gel electrophoresis with the DNA.
C) Pick a bacterial colony and test it to see if -galactosidase is functional within the bacterial cells.
D) Pick a bacterial colony and retest it on ampicillin-containing plates to double-check that the cells are really ampicillin resistant.
E) Both c and d should be conducted.