pAT153 is an ampicillin and tetracycline resistant, general purpose cloning vector. It is a derivative of
pBR322 produced by the deletion of the bom (basis of mobility) site. This 703 bp deletion included the region involved in copy number control. Loss of this region gives pAT153 a 1.5 to 3-fold higher copy number. pAT153 is non-mobilizable and is more readily contained than pBR322.