DNA Extraction Lab

In this lab the main question that we were trying to find was "How can DNA be seperated from cheek cells in order to study it"? We found that DNA can be seperated from the cheek cells when it is placed in the 95% isopropanol alcohol solution. our qualitative data shows that this is the case because before the alcohol solution (homogenization stage) there was a thick layer of mucus, but after the alcohol solution was added (precipitation stage) a clump of what looked like spongy meterial began to float to the surface. This material was the DNA that had been extracted from the mucus. In order to get the DNA alone we had to break down the proteins known as histones. We did this by adding pineapple juice witch contained catabolic proteases witch are good at decomposing proteins. Although my results were accurate and reasonable i did make a few errors. My biggest flaw in this experiment was the fact that i forgot to add sodium chloride (salt) into the solution. This would have facilitated the precipitation by shielding the negative phosphate ends of the DNA, allowing them to move closer together. Our overall data contradicts the expected results because of my failure to put sodium chloride into my solution. The results might have been affected because there would be more phosphate ends in my clump of DNA because the solution failed to shield and move them closer together. Two ways i could improve this lab would be to reread the directions and make sure that all the ingredients for the solution are put in, and be more precise about how much of each ingredient i put in the solution. The purpose of this lab was to better help us understand DNA and what compositions break down proteins. I could apply what i learned in this lab to my knowledge when taking tests. I will be able to remember what proteins are composed of and what solutions break them down.