The features required for cloning in a vector are as follows :
Selectable Market : Along with 'Ori' the vector also requires selectable markers, which are helpful in identifying and eliminating non-transformants and in selective selection of transformants. Transformation is a process by which a segment of DNA is introduced into the host bacteria. Generally, genes coding resistance to some antibiotics like Ampicillin, Chloramphanicol, Tetracycline or Cannamycin etc. is not found in E. coli bacteria because the genes showing resistance are absent in them. Therefore, E. coli is considered a good selectable marker.