Students use specially developed pBLU® plasmid in a colony transformation procedure to observe the phenotypic effect of inserting new genes into living bacteria. An ampicillin-sensitive strain of E. coli, incapable of producing β-galactosidase for lactose breakdown, is induced to take up pBLU® plasmid DNA. This plasmid contains genes for both ampicillin resistance and β-galactosidase production. The transformed cells are plated on (1) medium containing ampicillin, and (2) medium containing ampicillin and X-gal. (X-gal is a histochemical substrate that, when cleaved by β-galactosidase, forms a blue product.) Transformants appear as white colonies on the ampicillin medium and as blue colonies on the ampicillin/X-gal medium. The transformed colonies’ phenotype is lac+ and ampr.
** Kit and perishable components will ship separately and may arrive on different days.