What is the origin of replication and the plasmid copy number of the pQE vectors?
FAQ ID -338

The QIAexpress pQE vectors contain a pBR322 derived ColE1 origin of replication and are classified as low-copy plasmids (by our estimate, approximately 20-30 copies per cell; exact numbers have not been determined). The pQE-TriSystem Vector has a pUC origin of replication and is classified as a high-copy vector. Please see also FAQ 350 for general information on replication origins and copy numbers of various commonly used plasmids.