Plasmid DNA from Escherichia coli RRI confers ampicillin resistance and complement defects in β-galactosidase in appropriate host strains. The multiple cloning site (MCS) is within the β-galactosidase gene. pUC8 and 9 have nine unique sites within the MCS while pUC18 and 19 have thirteen.

Plasmid DNA from Escherichia coli RRI has been used in polymerase chain reaction (PCR).

Plasmid DNA from E. coli RRI has also been used for in vitro DNA transfection studies.

These plasmids confer ampicillin resistance and complement defects in β-galactosidase in appropriate host strains. The multiple cloning site (MCS) is within the β-galactosidase gene; pUC8 and 9 have nine unique sites within the MCS while pUC18 and 19 have thirteen.
Foreign DNA inserted at the MCS abolishes the ability to catabolize lactose. Lactose-positive, ampicillin-resistant colonies (host strain containing plasmid) form blue colonies on plates containing ampicillin and X-Gal; lactose-negative, ampicillin-resistant colonies (host strain containing plasmid with foreign DNA inserted at the MCS) form white colonies on this medium. The orientations of the MCS regions in the pUC plasmids are analogous to those of the corresponding M13 phage.

pUC18 Plasmid DNA, 10 μg is supplied at approximately 0.5 mg/ml in 10 mM Tris-HCl (pH 8.0) with 1 mM EDTA.

Foreign DNA inserted at the MCS interrupts the β-galactosidase gene and abolishes the ability to catabolize lactose. Lactose-positive, ampicillin-resistant colonies (host strain containing plasmid) form blue colonies on plates containing ampicillin and X-Gal; lactose-negative, ampicillin-resistant colonies (host strain containing plasmid with foreign DNA inserted at the MCS) form white colonies on this medium.