Draft: DNA Extraction

Today I performed DNA extraction in a labratory course. We took the leaves of a plant and ground it up using two metal balls inside the 2 mL roundbottom tube. The tube was attached to a machine that shook the tubes rapidly and rigorously for one minute. That was enought to crush the frozen leaves in a fine powder. Detergent and EDTA were added to the powder to break down the cell and nuclear membranes and stop enzymes from breaking down the DNA. The tube was heated and chilled. Next we added a potassium solution to the tubes to cause proteins and carbohydrates to precipitate, which they did. After centrifuging the tube, the supernatant containing the DNA was transferred to a new, clean 2 mL roundbottom tube. Isopronanol was then addded to the solution to cause the DNA precipitate, leaving behind lipids and remaining proteins and carbohydrates in the solution. The content was centrifuged once again, and this time, the pellet was what we wanted to keep, for it was the DNA. The resulting pellet was very small and almost clear. It appeared as a small, cloudy smudge on the bottom of the tube. We extracted the supernatant and washed the DNA pellet with 70% ethanol. The DNA pellet was then dissolved in a solution that would preserve the DNA to be able to be used far in the future.