Results - Bacterial Transformation Lab

The two plates in the top row in the photograph below were LB (left) and LB/Amp (right). Both plates were inoculated with untransformed (-DNA) bacteria. Notice that the LB plate contains abundant growth but the LB/Amp plate does not contain any colonies. The two plates on the bottom were LB/Amp (left) and LB/Amp/Ara (right). Both plates were inoculated with transformed (+DNA) bacteria. Bacteria that grow on these antibiotic-containing plates have been transformed. They picked plasmid DNA that contains a gene that gives them resistance to ampicillin.

The transformed bacteria picked up a gene that codes for green flourescent protein. This protein glows when illuminated by ultraviolet light. The gene is controlled by the arabinose operon and is therefore active only when arabinose is present in the culture medium (below, right).

In order to confirm that the transformed bacteria growing on the LB/Ara plate (lower left plate in the photograph above) are capable of glowing in the presence of arabinose, a sample was moved to an LB/Amp/Ara plate (below).