Reva Vaidya's Biology Blog : pGLO lab

Plate	Number of Colonies	Color of colonies under room light	Color of colonies under UV light
-pGLO LB	carpet	brownish yellow	whitish blue
-pGLO LB/amp	0	N/A	N/A
+pGLO LB/amp	150-200	brownish yellow	whitish blue
+pGLO LB/amp/ara	47	brownish yellow	glowing green

2. The bacteria gained two new traits. The bacteria in the "+pGLO/LB/amp/arab" glowed under UV light and gained resistance to ampicillin because they were able to survive in the ampicillin and grow into 47 colonies.

3. On the "+pGLO/LB/amp/arab" plate, there were around 47 colonies. There was a lot of empty space, almost 1/2 of the plate was empty. Each bacteria that transformed would have multiplied into a colony, therefore around 100 bacteria were in the 100 micro-liters, and half of them died. On the "+pGLO LB/amp" around 150 colonies were on the plate. However, since we spread the bacteria all around the plate and there are empty spaces, we must have put around 250 bacteria. On the "-pGLO/LB" there were many more bacteria than on the other plates that made it onto the plate because almost the entire plate was covered. On the "-pGLO/ LB/ amp", we do not know how many bacteria made it onto the plate because they all died on contact since they did not have the ampicillin resistance.

4. The glowing is caused by GFP or Green Fluorescent Protein. The GFP is "turned on" in the presence of arabinose, and starts expressing its traits. So arabinose causes the cells to glow green.

5. There are many uses of GFP for scientists. In cellular biology, GFP has been used as reporter gene, cell marker, fusion tag. This means that if the cell glows then the scientists know that whatever gene they inserted into the cell is also being expressed, because GFP is attached to that protein. In the early 1990s, molecular biologist Douglas Prasher, used GFP to design probes, a technology involving fragments of DNA to detect the presence of nucleotide sequences. GFP is also used to to make the resultant protein react to wider wavelengths and emanate different colors.

6. Genetic engineering can be used to alter crops so that they become more resistant to pesticides and pests. It can also be used to make bacteria mass produce insulin for diabetics.