The plasmid cloning vector pUC18 is widely used in E.coli.
A plasmid is a circular dsDNA molecule with a circumference of a few hundred or thousand base pairs. Plasmids are bacterium viruses that exist naturally.
Because of its modest size, pUC18 allows big DNA fragments to be successfully cloned.
In appropriate host organisms, the plasmid pUC18 transmits ampicillin resistance and complement deficiencies in beta-galactosidase.
The MCS region of pUC18 is inverted compared to pUC19. Both pUC18 and pUC19 allow you to clone restriction enzyme-generated DNA fragments in both directions towards the lac promoter.