DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus where it is called nuclear DNA, but a small amount of DNA can also be found in the mitochondria where it is called mitochondrial DNA or mtDNA. (U.S. National Library of Medicine, 2012)
Although DNA was discovered earlier, there still remains a lot to be known about it, especially how it is used to determine the physical traits that we all have, and how it regulates the workings of the body. DNA Extraction is the removal of deoxyribonucleic acid (DNA) from the cells or viruses in which it normally resides. Extraction of DNA is often an early step in many diagnostic processes used to detect bacteria and viruses in the environment as well as diagnosing disease and genetic disorders. (Rice, 2012) A. Extracting DNA from Plants
In this part of the experiment, DNA was extracted from the cells of onions. A buffer solution was used in this experiment for several reasons. First the table salt, this was used so that the DNA will like to dissolve because of the saltiness and acidity (pH) of the solution. Second, detergent was used to help break down cell walls in the onion cells. Because detergent is used to break apart greasy particles in your clothes, it will also work to tear apart the “greasy” molecules in cell walls. Cell walls in living things are made of long polar molecules with a “greasy” end and a charged end. It is important to break the cell walls because the DNA is inside the cell.
To slow down the rate at which the DNA breaks up, we cool down the buffer solution to near freezing, that is why the buffer solution was needed to put in an ice bath. As important as DNA molecules are to life, they are still fragile, and break apart easily when removed from cells. Chemical reactions always take place slower in cold solutions than in warm ones, because...
References: (1999). Extraction of DNA from an Onion. Cavalcade Publishing.
Rice, G. (2012, November 25). DNA Extraction. Retrieved November 26, 2012, from Microbial Life Eduactional Resources: http://serc.carleton.edu/microbelife/research_methods/genomics/dnaext.html
U.S. National Library of Medicine. (2012, November 19). What is DNA? Retrieved November 23, 2012, from Reference, Genetic Home: http://ghr.nlm.nih.gov/handbook/basics/dna
Collecting and Handling Saliva for DNA Analysis. (2009, August 19). Retrieved November 24, 2012, from Salimetrics: http://www.salimetrics.com
Science Education Partnership Award. (2012). DNA Extraction Virtual Lab. Retrieved November 24, 2012, from www.dna_extraction_virtual_lab.com
Please join StudyMode to read the full document