Human DNA Extraction Lab

In this lab, we asked the question: How can DNA be separated from cheek cells in order to be studied? During our research, we learned that the protocol for DNA extraction involved three basic steps: homogenization, lysis, and precipitation. We found that it was made possible by means of scraping our cheek cells with our teeth in the presence of Gatorade, adding salt, soap, and pineapple juice, and then finally applying a layer of cold alcohol at the top. The DNA floated to the alcohol with ease.

In order to break down the cell walls/membranes, plasma membranes, and nuclear material in the first step homogenization, the cell tissue must be submerged in a polar liquid, which in our case, was Gatorade. Inside the mixture of our saliva, Gatorade, and cheek cells, we could see the DNA a little bit better because of the breaking down of the cell membranes, plasma, and nuclear material. After adding soap, salt, and pineapple juice to the mixture, 95 percent isopropanol alcohol is layered carefully to the top of the mixture, and since alcohol is nonpolar and DNA is polar, the DNA falls out of the solution as a precipitate at the interface of the two solutions. After pulling it out of the alcohol layer, our DNA has been extracted.

While our hypothesis may have been supported by our data, there could have been possible errors due to the fact that many of the steps didn't have exact amounts of materials we were supposed to add. This could have affected the results because if we didn't have the right amount of something to add to the solution, the DNA may have not been able to be extracted properly. Also, we were supposed to come up with the procedures by ourselves, so if we did something that was not in the correct order, that could have messed up the process of extracting the DNA properly. I think that next time, maybe more precise amounts should be added to the procedure and the students should actually get the full procedures to prevent the possibility of just wasting materials by not being able to do the actual procedures.

This lab was done to demonstrate how DNA could be extracted from cheek cells and that DNA is not as complicated and unreachable as we may think. From this lab, I learned about concepts such as homogenization, lysis, and precipitation, which helps me better understand the concept of DNA as a whole. Based on my experience in the lab, if cloning is invented, I would definitely know how to extract my DNA to create a clone.