The Extraction of Deoxyribonucleic Acid

THE EXTRACTION OF DNA

THE EXTRACTION OF DNA
07/02/2013
| By Laura Green, Tasnim Rahman and Sandra Strammiello |

Table of Contents

DNA………………………………………………………………………………………..………… 2
The Discovery of DNA…………………………………………………………………………...…………..…………. 4
The Steps for Extracting DNA…………………………………………………………………………………………….…..… 5
Experiment: Which Product Can the Most Visible Amount of DNA
Be Extracted From?.................................................................................................................. 7
Bibliography………………………………………………………………………………………..9

DNA

What is DNA?
DNA is a molecule called deoxyribonucleic acid which contains the biological instructions, meaning it explains about living species; it makes each species unique. It is passed from adult organisms during reproduction, along with the instructions it contains. Where is DNA Found?
DNA is found inside the nucleus of a cell. Organisms have many DNA molecules per each cell. The nucleus of a cell is very small, and each DNA molecule is secured properly. This form of the DNA is called a chromosome.
During DNA replication, DNA untangles so it can be copied. At other times in the cell cycle, DNA untangles, so that its instructions can be used to make proteins and for other living methods. But during cell division, DNA is in its compact chromosome form to approve transfer to new cells.
Researchers refer to DNA found in the cell's nucleus as nuclear DNA, which is an organism's complete set of nuclear DNA, and is called a genome.
Besides the DNA based in the nucleus, humans and other complicated organisms also have a small amount of DNA in cell formed as mitochondria. Mitochondria generate the energy, which the cell needs to function properly.
In sexual reproduction, organisms take over half of their nuclear DNA from the male parent and half from the female parent. However, organisms take over all of their mitochondrial DNA from the female parent. This happens because only egg cells, and not sperm cells, keep their mitochondria during fertilization.
What is DNA made of?
DNA is made up of chemical building blocks called the nucleotides. These building blocks are made up of three parts: A phosphate group, a sugar group and one of four types of nitrogen bases. To construct a strand of DNA, nucleotides are joined into chains, with the phosphate and sugar groups exchanging.
The four types of nitrogen bases which is found in nucleotides are: Adenine (A), Thymine (T), Guanine (G), and last but not least, Cytosine (C). The order of these bases control what living information is found in a strand of DNA.
DNA bases pair up with each other, A with T and C with G, to construct units called base pairs. Each base is also attached to a sugar molecule and a phosphate molecule.
What does DNA do?
DNA contains the instructions needed for an organism to progress, survive and reproduce. To carry out these functions, DNA codes must be changed into messages that can be used to produce proteins, which are the complex molecules that do most of the work inside our bodies. The Double Helix Form
Sugar and phosphate as a combination is called a Nucleotide. Nucleotides are positioned in two long strands that form a spiral called a double helix. This looks like a twisted ladder and the base pairs (A, T, G, and C) form the groups of the ladder, and the sugar and phosphate molecules form the sides of the ladder.

The Discovery of DNA
In 1953 James Watson, Francis Crick, Maurice Wilkins and Rosalind Franklin all had their part in discovering the structure that is DNA. In 1962 Crick, Watson and Wilkins won a Nobel prize. Rosalind Franklin was not recognized for her contribution to the discovery because she died of cancer at the age 37 so only the rest of the team was honored with the award. Of the four scientists only Rosalind Franklin had any degrees in chemistry. DNA has patterns for making proteins in the body, including the various enzymes. It took them very long to figure out what DNA was and how it worked. The man that helped those brilliant scientists was Friedrich Miescher was working 1800’s separated what he called “ nuclein “ from cells. Using complicated procedures he proved the new substance was from the nuclei and it was a new type of organic molecule not like anything known at the time. They all reached a big conclusion in 1953 that DNA molecule exists in the form of a three-dimensional double helix.

The Steps for Extracting DNA
Extracting DNA takes about three of four simple steps: First, the cell must be broken open to reveal the nucleus. Second, the nucleus must also be opened to release the DNA. Third, the DNA then needs to be precipitated in alcohol. These are four simple steps I followed for the extraction of DNA:
Step One: Breaking Open the Cells.
Blend half a cup of your chosen substance with ⅛ of a teaspoon of salt and 1 cup of cold water. Blending helps to separate the cell walls, cell membranes and nuclear membranes. The salt weakens the lipid walls, which is a must in breaking open the cell and also helps the DNA precipitate in the presence of alcohol. The cold water slows down the enzymatic reactions, which protects DNA from enzymes that can destroy it. A cell’s DNA is usually protected by such enzymes by the nuclear membrane, but the detergent that is later added, destroys that membrane.
Step 2: Breaking Open the Nucleus.
Pour your substance through a strainer and into a clear container. Add 2 tablespoons of liquid detergent of your choice and gently swirl the container to mix the detergent with the blended substance. Adding detergent helps break through the cell membrane, the lipid walls and break open the nucleus to reveal the contents hidden in the cell, including the DNA. Now pour the mixture into three separate test tubes.
Step 3: Removing the Protein from the DNA.
Add a pinch of enzymes to each test tube and stir very gently so you won’t break up the DNA and make it harder to see. The enzymes help remove the proteins that mold, fold and protect the DNA in the nucleus of the cell. Two common enzymes, Bromelain and Papain, are found in meat tenderizers, which is what I will be using as an enzyme. Bromelain and Papain are both proteases which means they break apart proteins.
Step 4: Precipitate the DNA.
Slowly pour alcohol into your mixture. DNA normally dissolves in water, but with the salt added into it from the first step, the DNA reacts with the alcohol, forming a precipitate making the DNA visible. The DNA will clump together when there is it, which is why the DNA you will see will be clumped together. All the other cell components stay at the bottom of the mixture due to the fact that they are not soluble in alcohol.

Experiment:
Which Product Can the Most Visible Amount of DNA be Extracted From?
-grapes -strawberries
-raisons -raw chicken
In this experiment, the goal is to compare the amount of visible DNA extracted using four different food substances. We are using a dish soap with the pH level of 8, which is a little bit more than neutral, but still basic, 3% cold salted-water and 50% isopropyl alcohol. Our hypothesis is that the raw chicken and strawberries will show the most visible amount of DNA, because the strawberries have the most seeds, which must contain a lot more DNA than the raisins and grapes. The raw chicken will show the most visible amount of DNA because it is part of an animal with a lot of cells, which contain DNA. Going through each of the steps carefully and as precisely as possible, we obtained these results:
The raw chicken, with the most amount of visible DNA:

The strawberries, with the second most amount of visible DNA:

The raisins, with the second to last most amount of visible DNA:

The grapes, with the least amount of visible DNA:

Bibliography http://www.isgtw.org/feature/keeping-top-data-deluge http://genegeek.ca/2012/08/what-is-dna/ http://ghr.nlm.nih.gov/handbook/basics/dna http://www.genome.gov/25520880 http://learn.genetics.utah.edu/content/labs/extraction/howto/faq.html http://genetics.thetech.org/about-genetics http://serc.carleton.edu/microbelife/research_methods/genomics/dnaext.html http://learn.genetics.utah.edu/content/labs/extraction/ http://genetics.thetech.org/online-exhibits/do-it-yourself-strawberry-dna http://sciencenetlinks.com/lessons/extracting-dna/ http://learn.genetics.utah.edu/content/labs/extraction/howto/ http://publications.nigms.nih.gov/thenewgenetics/chapter1.html http://en.wikipedia.org/wiki/DNA https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcQI3CWNGlxS7IL3kZoQEcbyKlW06E_1Fs_SRpqDfE24IZVicTsj
http://www.funxite.com/get/msn/msn-backgrounds/miscellaneous-msn-backgrounds/dna-msn-background.htm