Onion DNA Extraction Essay

DNA(deoxyribonucleic acid) is found in every living organism. It provides the information and instructions to build and regulate cells in organisms. The information it contains is used when organisms are being reproduced. It is made up of two polynucleotide chains known as DNA strands. Within the two chains there are four nucleotide units: adenine, thymine, cytosine, and guanine. Materials and Methods An onion was cut into pieces and placed in a blender with 50 mL of water and blended for one minute. Once blended, 20 mL of 25% saline solution and 10 mL of liquid detergent was added to the mixture and blended for 3 minutes. The mixture was then added to a flask and placed into a bath of hot water at 42? C for 10 minutes. The mixture was then removed from the hot water bath and filtered using a cheese cloth (dryer sheet) into a beaker. In a test tube (test tube â€Å"B†), 10 mL of 90-95% ethanol was placed into a beaker filled with ice. Then 10 mL of the filtered mixture was then placed into a test tube (test tube â€Å"C†). Test tube â€Å"C† was tilted at an angle and the ethanol from test tube â€Å"B† was slowly poured into test tube â€Å"C†. After 5 minutes, a white layer was formed between the onion-detergent mixture (test tube â€Å"B†) and the ethanol (test tube â€Å"C†). A plastic pipette was used to remove the white layer from the tube and placed into a micro centrifuge tube. The micro centrifuge tube was centrifuged at 10 K rpm for 1 minute. The supernatant in the tube was then removed and discarded only leaving the white pellet that was formed at the bottom. Results During this experiment, the DNA of the onion had formed at the bottom of the micro centrifuge tube.