Without a selectable marker, it becomes challenging to distinguish between cells that have taken up the cloning vector with the desired DNA insert and those that haven’t. This makes the process of identifying and selecting transformed cells much more difficult. Selectable markers, such as antibiotic resistance genes, allow for the growth and selection of only those cells that have successfully taken up the vector, simplifying the cloning process by enabling the isolation of transformed cells. Therefore, the absence of a selectable marker significantly hinders the efficiency and success of the cloning process.
