A
cloning vector is a small piece of
DNA, taken from a
virus, a
plasmid, or the
cell of a higher organism, that can be stably maintained in an organism, and into which a foreign DNA fragment can be inserted for
cloning purposes. The vector therefore contains features that allow for the convenient insertion or removal of DNA fragment in or out of the vector, for example by treating the vector and the foreign DNA with a
restriction enzyme that creates the same overhang, then
ligating the fragments together. After a DNA fragment has been cloned into a cloning vector, it may be further
subcloned into another vector designed for more specific use.