A
multiple cloning site (
MCS), also called a
polylinker, is a short segment of
DNA which contains many (up to ~20)
restriction sites - a standard feature of engineered
plasmids. Restriction sites within an MCS are typically unique, occurring only once within a given plasmid. MCSs are commonly used during procedures involving
molecular cloning or subcloning. Extremely useful in
biotechnology,
bioengineering, and molecular genetics, MCSs let a molecular biologist insert a piece of DNA or several pieces of DNA into the region of the MCS. This can be used to create transgenic organisms, also known as
genetically modified organisms (GMOs).