Third times the charm




Figure 1
Ruler  E. Coli S Aureus, Bacillus Agrobacterium
 

Last week I worked on my DNA extractions. The bacteria I worked on were E. Coli, S. Aureus, Bacillus, and Agrobacterium. To test if my extractions were successful I ran a gel for each. I have some pictures of what I see after running the gel. I allowed the gel to run for 35 minutes at 120 volts, when that was done I placed it under UV light, and that light allows us to see if DNA is present or not. The reason we check if DNA is present this way is because to each sample I add two different dyes if any of you recall, one of them (orange dye) gives the DNA bonds higher resolution  in the agarose gel while the syber green stains the nucleic acid bonds from the DNA allowing it to absorb blue light (UV light) and emits a green color. When I place the gel under this UV light I should be able to see green light for each of my samples showing the existence of DNA including the ruler. For example in figure 1 (my first extraction), you can only see about three bacteria not including the ruler. The ruler has about 5 bright dots in its row. You can only see a big dot for E. Coli, a small dot for Bacillus, and just a line for Agrobacterium. This extraction worked for those three bacteria but failed for the S. Aureus, but none of the samples actually ran all the way down like the ruler did. This gel is 1% agarose a normal percentage to use for a gel, but in this case this gel was too concentrated and for this reason the samples did not run all the way down like they should have. If you notice the only bright bands you see at the other side of the rectangle is the rulers, not the bacteria's DNA. On figure 2 (my second extraction) though, you can see a bright light for all of them, even though you can barely see the S. Aureus band. This extraction worked for all four but even though the gel concentration was changed to .5%, the samples did not run all the way down. Figure 3 (my third extraction) though is the best extraction I have done so far. You can notice the difference in the brightness, and the length that each travelled ( almost to the ruler). By length I mean how far each sample ran to the bottom part of the rectangle.




Fgure 2
Ruler E. Coli S Aureus, Bacillus Agrobacterium
 

Figure 3
Ruler E Coli S Aureus Agrobacterium Bacillus