Question

Why is insertional inactivation preferred over the use of selectable markers in cloning vectors?

Answer 1

Insertional inactivation is preferred over selectable markers in cloning vectors because it allows for easy identification of recombinant plasmids without further selection methods. Insertional inactivation involves a cloning vector containing a reporter gene disrupted by the DNA fragment insertion site. The successful integration of a DNA fragment impairs the reporter gene, resulting in a loss of function that is visually detectable. This method optimises the cloning process and removes the requirement for antibiotic selection, enhancing convenience and cost-effectiveness.