Multiple cloning site

A multiple cloning site (MCS), also called a polylinker, is a short segment of DNA which contains many (usually 20+) restriction sites - a standard feature of engineered plasmids. Restriction sites within an MCS are typically unique. In other words, they only occur once within that particular plasmid. MCSs are commonly used during procedures involving molecular cloning or subcloning. Extremely useful in biotechnology, bioengineering, and molecular genetics, MCSs let a biotechnologist 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).