How to Extract DNA From Fruits INTRODUCTION In recent years, it is not uncommon

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How to Extract DNA From Fruits

INTRODUCTION

In recent years, it is not uncommon to read articles on DNA in both scientific and popular magazines. DNA is regularly mentioned in the news and is often featured in TV detective or crime-scene investigation dramas. DNA, also known as DeoxyriboNucleic Acid, is a long molecule that holds the genetic information for all living beings, be it vegetable, animal or a simple microorganisms. It is capable of copying itself and can synthesize RNA (RiboNucleic Acid). In more evolved or complex forms of life, DNA is contained in the nucleus of the cells. Except for the red blood cells of mammalians, which are devoid of a nuclei, all cells of a living being have their own DNA. The cells of an organism use certain parts of the DNA molecule, or genes, to produce the proteins they need to function. For a more detailed description of DNA including its structure, its functions and the mechanism by which proteins are produced, the reader should consult the texts listed [1] the Reference section of this paper, which are well written and contain excellent illustrations. In this article, I describe a simple experiment that will allow you to extract a bit of DNA from a banana, however, you can also try it using other fruits and even vegetables. It is an experiment that can be performed both at home and in a school laboratory

Summary of procedure

The procedure described below exploits the fact that the external membrane of cells and that of their nuclei are composed of fatty substances that can be broken down using a simple detergent. The first operation in this procedure is to break-up the fruit into a pulp or mush so that the cells are separated each from other as much as possible thereby exposing them to the action of the detergent. Secondly, the detergent is added to the pulp of the fruit so as to release the DNA from the cell membranes, which encapsulate it. Thirdly, it is necessary to filter the mixture to separate the nucleic acid from the remains of the cellular membranes. Finally, the DNA is precipitated in alcohol where it becomes visible. The DNA you obtain using this procedure can be observed with a microscope and can be used for other experiments like electrophoresis or other experiments.

1. What type of organisms and cells contain DNA?

2 What is the role of DNA in organisms?

3. Why would you want to extract the DNA from the organism?

4. In the procedure, why is the banana crushed or ground up into a pulp?

5. Why is detergent added to the pulp?

6. Look up the meaning of the term “bain-marie” (I have never heard of it either.) What is a bain-marie? Give a reference.

7. What is a good natural source of protease?

8. What does a protease do?

9. Compare the solubility of DNA in water and in alcohol.

10. What is the difference between a filtrate and a precipitate? If you don’t know, look it up. You need to know in order to perform the experiment properly.

11. Macroscopically, what did your DNA look like? Was it pink as in the lab write-up? Try to pull some out with a stick or a tweezers. What’s it like?

12. what did you observe?

Explanation / Answer

1. DNA (Deoxyribonucleic acid) is a tool, used to store genetic informations in organisms. The cells of all plants and all animals contain DNA at the chemical level. We can say, all living organisms have DNA.

2. ROLE OF DNA:

3. Extraction of DNA is done to show that external membrane of cells and their nuclei are composed of fatty substances and can be broken down using a simple detergent.

4. Pulp is grounded to separate the cells from one another as much as possible , to expose them to the detergent.

5. The purpose of adding detergent is to release the DNA from the cell membranes, which encapsulate it.

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