A researcher is comparing the efficiency, fidelity, and methodology of in vivo gene cloning (using plasmids in Escherichia coli) with in vitro gene cloning (using the Polymerase Chain Reaction, PCR).
Which of the following statements regarding these cloning techniques is incorrect?
In vivo cloning relies on marker genes, such as those encoding fluorescent proteins or antibiotic resistance, to identify host bacterial cells that have successfully taken up the recombinant plasmid.
In vitro cloning via PCR requires a thermostable DNA polymerase because the high temperature (95∘C95^\circ\text{C}95∘C) used to anneal the primers to the template DNA would otherwise denature standard eukaryotic polymerases.
In vivo cloning requires the enzyme DNA ligase to form phosphodiester bonds between the target DNA fragment and the vector, whereas PCR does not require DNA ligase to synthesise copy DNA.
In vitro cloning is highly susceptible to trace DNA contamination because any foreign DNA with complementary primer sites will be amplified, whereas in vivo cloning is less sensitive as free linear contaminant DNA cannot replicate inside host cells.
