DNA isolation is a process of purifying DNA from the sample using a combination of physical and chemical methods. The first isolation of DNA was carried out in 1869 by Friedrich Miescher. DNA stands for deoxyribonucleic acid. It is made up of two strands that wrap around each other in a shape called a double helix. There are also four bases that make up DNA: adenine, guanine, cytosine and thymine. Each base pairs its specifications such that adenine always pairs with thymine and guanine with cytosine. Since Miescher's discovery, many advances have been made in DNA, such as defining its structure, discovering what DNA is made of, and the art of DNA extraction. Friedrich Miescher was a Swiss doctor and the first scientist to isolate DNA in 1869 (Tan). “Using arduous and complicated procedures, Miescher demonstrated that the new substance actually came from cell nuclei, and that it was a fundamentally new type of organic molecule, unlike anything known at the time” (Dahm, 2008). DNA extraction is the removal of DNA from the cell from which it originated. The DNA extraction process is now easier and can be performed in high school classrooms. The process involves first opening the cell or virus that contains the DNA. This is called lysis of the cell. This is commonly achieved by chemical and physical methods: mixing, grinding or sonicating the sample. Then the DNA is mixed with ethanol or isopropanol and centrifuged. This helps extract DNA because DNA is insoluble in alcohol. Then the DNA pellet is washed again with alcohol and centrifuged once again to obtain the final DNA pellet. Once the pellet is dry, the DNA is added to a buffer and then its presence is confirmed by gel electrophoresis or under a UV light. A diphenylamine... at the center of the document... tested on stool samples collected from 3 patients with inflammatory bowel disease and 5 healthy individuals.4. Rice, G. (n.d.). DNA extraction. Retrieved from http://serc.carleton.edu/microbelife/research_methods/genomics/dnaext.htmlDNA extraction removes DNA from the cells or virus from which it came. To extract DNA the cell must open or lyse. The three instruments used for DNA extraction are a beater, a centrifuge and a gel box.5. Tan, South Carolina (n.d.). DNA, RNA and protein extraction: the past and the present. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2789530/ There are many techniques used to extract DNA. There are solution-based and column-based protocols. The process of DNA extraction and purification is now simpler than before. Now there are automated systems in laboratories that have high sample production.