March 2, 2015
In this laboratory experiment, students were introduced to DNA electrophoresis. DNA electrophoresis is an instrument that many forensic scientists use to get a DNA fingerprint as an evidence for crimes. Not only can it be used for forensic science, people can use this for paternity test, as well as look for evolutionary relationships among organisms. Agarose is used to make the gel that the DNA fragments are going into. Since DNA particles are negatively charged, the gel is placed in a chamber with positively and negatively charge cords on each side of the chamber in order to separate different DNA fragments. The distance that DNA fragment travels depend on its size and polarity. The farthest that the band of DNA travels to the positive side, the smaller the DNA fragments.
DURING THE LAB
For this lab experiment, the mixture of agarose was already pre-made for the students. Students took the warm mixture out of the warm water bath and was instructed to pour the agarose into the gel casting tray that was taped on both side to prevent liquid falling out. After ten to fifteen minutes of waiting for the agarose to solidify, the tapes were removed from both sides and it was placed in the electrophoresis chamber. The students pipetted the dye into the three samples that were given out by the instructor, and loaded each sample into the wells of the gel. After the samples were placed into the gel and closed the lid of the chamber, the power supply was then turned out and make the DNA fragments to travel across the gel. After about thirty minutes of running the gel with the power supply, the casting tray was then taken out and placed into a tray filled with buffer solution.
The result of this DNA lab was that there were no result or data collected from running the DNA sample in the DNA electrophoresis. There’s appear to be an experimental error that have caused this outcome. In the lab handout, it said that in