To Isolate DNA from Available Plant Materials Such As Spinach, Green Pea Seeds, and Papaya

Introduction 

Do you know humulin is the artificial insulin protein synthesized using rDNA technology? How is it synthesized? rDNA is the technology used to make insulin and other products. This technology also helps in the production of genetically modified organisms. rDNA technology involves the isolation of DNA and the formation of new DNA combinations. At present time all human knowledge is directed to the comfort and well-being of human life by developing various technologies. Biotechnology is also one such technology directed to comfort human life.

Table of Content

• Aim

• Apparatus Required

• Theory

• Procedure

• Observations

• Result

• Precautions

• Lab Manual Questions

• Viva Based Questions

• Practical Based Questions

• Conclusion

Aim

The experiment aims to isolate DNA from plant materials such as papaya, green peas seeds, and spinach

Apparatus Required

The following apparatus is required for the experiment 

• Papaya, green pea, or any available plant material 

• Test tubes 

• Ethyl alcohol 

• Spool 

• Mortar and pestle 

• Enzymes( for digesting other cell material)

• Beakers

Theory

DNA is the genetic material of all plant cells. It is found in the nucleus of all cells. Genetic engineering is the technique of altering the genetic material of organisms to bring changes. Now to modify genetic material we need to isolate it.

The following are the steps involved in the isolation of DNA from cells-

• The cell is disassembled to release the DNA molecules as well as other macromolecules such as polysaccharides, proteins, RNA, and also lipids. This is done by treating the cells with different enzymes. Depending on the type of cell used for the isolation of genetic material different enzymes are used such as lysozyme used in bacterial cells, cellulase used in plant cells, and chitinase used in fungi.

• Ribonuclease is the enzyme used to remove RNA from cells.

• The proteins are removed using protease. These are the enzymes used to break protein.

• Ethanol is added to precipitate the DNA.

• The purified  DNA can be collected. 

Hence these are the steps used for the isolation of any genetic material from cells.

Procedure

• First, take any available plant material and then grind it with the help of a mortar and pestle

• After grinding mix it with cellulase enzyme, to break the cell wall of the cell. 

• After removing the cell wall, mix it with the protein-digesting enzyme protease.

• Then RNA is digested by the ribonuclease enzyme 

• The lipid content of the cell is dissolved by using a lipase enzyme.

• After removing or breaking all content of the cell, except DNA add chilled ethanol to facilitate the precipitation of DNA, it helps to increase the DNA concentration.

• Precipitated DNA is extracted by the spooling process. Spooling process is defined as winding the fine threads of DNA on a reel 

DNA Extraction 

Observations

After extraction, DNA seems like a white precipitate of thread on the spool.

Results

The DNA is extracted and observed as a white precipitate. 

Precautions

Following precautions must be taken while performing the experiment

1. The plant material should be washed with distilled or cleaned water to remove dust particles.

2. The enzymes and chemicals used in the experiment must be of standard quality 

3. All instruments such as glassware must be cleaned and dried

Lab Manual Questions

1. Why is salt added to DNA?

Ans: Salt is always added to DNA because it facilitates DNA to precipitate when alcohol is added to the solution.

2. Why is a chilled condition required during the experiment?

Ans: The main reason for maintaining a chilled condition during the experiment is to protect DNA from cellular enzymes and also to increase the yield of DNA.

3. Why is the enzyme cellulase used for isolating genetic material from plants?

Ans: The cellulase enzyme is used for digesting the cell wall of plant cells.

4. What is biotechnology? 

Ans: It is a branch of science that deals with the utilization of live organisms to make various products.

Viva Based Questions 

1. What is recombinant DNA?

Ans: Recombinant DNA is the DNA formed by manipulating and Isolating DNA through various lab techniques. 

2. What are genetically modified organisms?

Ans: Genetically modified organisms are made by altering the genetic material of organisms using genetic engineering techniques. 

3. What is the role of detergent in the isolation of DNA?

Ans: Detergent is used to break the cell so that DNA can be released from the cell. 

4. What are the roles of enzymes in the isolation of DNA?

Ans: Various enzymes are used to break the various content of the cell such as carbohydrate, protein, and RNA 

5. What is biotechnology?

Ans: Biotechnology is the technique of utilizing live organisms, and their parts to make different products. 

6. What types of nucleic acids are found in organisms?

Ans: Deoxyribonucleic acid and ribonucleic acid are found in organisms. 

7. Describe the steps involved in the isolation of DNA.

Ans: The main steps of DNA isolation are - the creation of lysate, clearing of the lysate, binding, washing, and elution. 

8. Why is DNA genetic material in most organisms?

Ans: DNA acts as genetic material in most organisms because it is chemically and structurally stable. 

Practical Based Questions

Q1. Quantity of DNA in the given plant material can be estimated by which instrument?

1.  spectrophotometer 

2. Manometer

3. Thermometer

4. None of the above

Ans: (1) spectrometer 

Q2. Which of the following chemicals is used for chilling ethanol?

1. Methanol

2. Ethanol

3. Acetaldehyde

4. None of the above

Ans: (2) Ethanol

Q3. Which of the following enzymes is used for the denaturation of protein while carrying out DNA isolation? 

1. Chitinase

2. Lysozyme

3. Protease

4. All of the above

Ans: (3) protease

Q4. Which enzyme should be used for the isolation of DNA from fungus?

1. Protease

2. Amylase

3. Chitinase

4. All of the above

Ans: (3) chitinase

Q5. Which of the following methods is used for DNA isolation?

1. Phenol chloroform method

2. Silica gel membrane method

3. Salting out and proteinase k treatment method

4. All of the above

Ans: (4) All of the above

Q6. Which of the following is the step of DNA isolation?

1. Washing

2. Elution

3. Clearing of lysate

4. All of the above

Ans: (4) All of the above

Q7.  Who discovered DNA isolation?

1. F. Miescher

2. Rosalind Franklin

3. Watson

4. None of the above

Ans: (1) F. Miescher

Q8. Double helix model of DNA was given by

1. Watson

2. Crick

3. Both of the above

4. None of the above

Ans: (3) Both of the above 

Conclusion 

• In this article, we have learned an experiment on the isolation of DNA from available plant materials such as spinach, green seed pea, and papaya

• We have also explained the DNA extraction diagram in this article

• DNA can be isolated from any cell by following certain steps

• After chilled ethanol is also added to facilitate the extraction process of DNA. 

• DNA is extracted in the form of white suspension thread on the glass rod.