What is a selectable marker?

Selectable markers:

1. The selectable marker is the sequence of DNA.
2. It helps in identifying and eliminating non-transformants and selectively permitting the growth of transformants.
3. The vector requires a selectable marker for this purpose.
4. A selective marker is required for the maintenance of plasmid in the cell.
5. Because of the presence of the selective marker, the plasmid becomes useful for the cell.
6. Under selective conditions, only cells that contain plasmids with selectable markers can survive.
7. Genes that confer resistance to various antibiotics are used.
8. Genes that make cells resistant to ampicillin, neomycin, or chloramphenicol are used.