Question

Suppose that you carried out a Bacterial transformation of E. coli HA101 with pGLO plasmid experiment in the lab. During the experiment plates with bacteria were inoculated from +GLO and -GLO microfuge tubes (LB (-) plate, LB/amp (-) plate, LB/amp (+) plate, and LB/amp/ara (+) plate).

14) Explain what kinds of bacterial growth you will find on each of 4 plates after incubation ((LB (-) plate, LB/amp (-) plate, LB/amp (+) plate, and LB/amp/ara (+) plate): under normal light and under UV light. Did some bacteria acquire new traits? Which ones? How do you know?

15) If the genetically transformed cells have acquired the ability to live in the presence of the antibiotic ampicillin, then what might be inferred about the genes on the plasmid that you used in your transformation procedure?

16) After performing transformation procedure and incubating bacteria for 48 hours at 37℃, can you tell if these bacteria are ampicillin resistant by looking at them on the LB (-) plate? Explain your answer.

Answer 1

14. LB (-) plate - There will be growth on the plate as E. coli HA101 will grow on LB media under normal light.

LB/amp (-) plate - There will be no growth as E. coli HA101 cells are not resistant to ampicillin when the plate is observed under normal light and UV light.

LB/amp (+) plate - There will be growth on the plate as E. coli HA101 cells with pGLO plasmid are resistant
to ampicillin under normal light. The growth on the plate may not be responsive to the UV light.

LB/amp/ara (+) plate - There will be growth on the plate as E. coli HA101 cells with pGLO plasmid are resistant
to ampicillin under normal light. The growth on this plate will also be responsive or clearly seen under UV light due to production of green fluorescence protein(GFP) as arabinose turns on the gene for GFP production.

Yes, some bacteria acquired new traits. E. coli HA101 cells with pGLO plasmid will be able to grow on ampicillin as they became resistant with transformation.

15. As the genetically transformed cells have acquired the ability to live in the presence of the antibiotic ampicillin,
we can infer that the ampicillin resistant gene is present on the pGLO plasmid used in the transformation procedure.

16. No. we can not tell if those bacteria are ampicillin resistant by looking at them on the LB (-) plate because of the following reasons:-
i. We have plated E. coli HA101 cells without pGLO plasmid which contains the amplicillin resistant gene.

ii. We have not used ampicillin in the LB (-) plate.