The pGEM-3Z vector is used as a standard cloning vector, as well as for highly efficient synthesis of RNA in vitro. It is very similar to pUC vector as it carries ampicillin resistance (ampR), MCS, lacZ genes, and additionally it contains short sequences of DNA (SP6 and T7 RNA polymerase promoters) flanking MCS, each of which acts as the recognition site for the attachment of RNA polymerase enzyme.