The first step in this experiment was to add plasmid DNA, the “mini chromosomes” of the bacteria, to the E. Coli cells in order to change the genetic makeup of them. I then added 10 LU_ of the plasmid to tube two. The next step was to chill both the tubes E. Coli cells in an ice bucket for twenty minutes. Once the twenty minutes pass, I took the cells out of the ice and quickly shocked them with a hot, 42-degree Celsius water bath. Then I removed the E. Coli cells from the 42-degree water and transferred them into a 37-degree Celsius water bath for the next 60 minutes.
While waiting, I obtained four Petri dishes, two with just LB agar and the other two with the LB agar plus inclining. I labeled the two plates without inclining A and B and the two plates with inclining C and D. After the 60 minutes had passed, take the E. Coli out of the bath and pipette 100 LU of cells from the first tube (no plasmid) and spread onto plates A and C. With the second tube, pipette 100 LU of cells onto plates B and D. Using five sterile glass beads spread the E. Coli cells around the Petri dishes. Place all of the Petri dishes into a 37-degree incubator for about twelve to sixteen hours.
After that time had passed, I stored the plates in the refrigerator until I came back one week later to view the results. After the week passed, I checked the plates to see how much the E. Coli cells grew and checked the fluorescence in a dark room. Results: After the week my results are as shown in the table. Plate A and B had a lot of cell growth with no fluorescence. Plate C had no cell growth and no fluorescence. Plate D had almost 70 colonies of cells with fluorescence. Number of colonies present Plates fluorescence Plate A Lawn of cells No Plate B Lawn of cells No
Plate C None No Plate D About 68 yes Discussion: Based on the results of my experiment, my predictions were mostly correct. The plates that had no inclining had a lot of growth and the plates with plasmid injected E. Coli both were able to grow cells and became bluestocking. The only result that was not predicted was that there was no fluorescence on Plate B when it was expected. This can be explained because the plate becomes overpopulated with E. Coli cells and the plasmid DNA is not 100% successful in changing the genetic composition of the E. Coli.
So, there really is luminescence but there are just so many cells that you cannot always see it. My results were pretty similar to the results of the rest of the class. Based on the results, my hypothesis is also correct because changing the DNA of the E. Coli cells causes genetic changes. In this experiment, the DNA caused the cells to be immune to the inclining and still able to reproduce. This experiment shows that there is a need to have concern for the development of different strains of bacteria or the change of these bacteria that can affect the health of many.