DNA contains the genetic material for all of the cells in our body. It is contained in the nucleus of a cell and codes for all of the proteins made in our body. It is a double stranded helix that is composed of a phosphate a sugar and a base. It has 4 bases. The purpose of this lab is to precipitate our own DNA from our cheek cells and place it in a glass tube. To do this we have to swab the inside of our cheek and place it in a test tube. We had to swish a cup of salt water around in our mouths to help get the DNA, then we poured the lysis buffer into the tube with our DNA. Then we had to invert the tube to mix the lysis buffer with the water and DNA in the tube. Then we added protease to kill the DNAse that kills DNA. Then we had to place the beaker in a hot water bath so the protease would perform at its highest level for 10 min. Once we got the tube out of the water bath we had to place 10 mL of alcohol in the tube. After that we just had to wait and watch the DNA precipitate.
Once we had the DNA precipitated it appeared as white strands floating in the glass tube we placed it in. It was really cool to see what our own DNA looked like and how much there was for only a small amount of cheek cells. I also thought it was weird once Mr. Chugh explained that there is an enzyme that kills DNA strands because I didn't understand why our body would want to destroy DNA. But then I understood more once he explained that it was for foreign DNA like viruses. That also helped explain why DNA doesn't leave the nucleus, because DNAse is not in the nucleus so it would only kill the DNA of invading cells. I enjoyed being able to walk out of the classroom with a tube of my own DNA hanging around my neck and explaining to people what it was.
