DNA Cloning

Table of Contents

• What is DNA Cloning?
• DNA Cloning Steps
• Importance of DNA Cloning

“DNA cloning is a molecular biology technique which is used for the creation of exact copies or clones of a particular gene or DNA.”

DNA cloning is the process of making multiple copies of a particular segment of DNA. During this technique, the selected DNA fragment is inserted into a plasmid (the circular piece of DNA) using enzymes. Restriction enzymes and DNA ligase are used in the process.

The restriction enzymes are used to cut the DNA fragments at specific sequences and DNA ligase enzymes are used to join the nicks. The recombinant DNA thus produced is introduced into bacteria. These bacteria reproduce and produce an exact copy of the plasmid. These copies are known as clones.

Also Read: DNA Structure

DNA Cloning takes place in the following steps:

Cutting and Pasting DNA

Two types of enzymes are used in this method:

• Restriction enzymes
• DNA ligase

The restriction enzymes cut the DNA at specific target sequences. The target gene is inserted into the cut site and is ligated by DNA ligase. This is known as a recombinant plasmid.

Bacterial Transformation and Selection

The recombinant plasmid is introduced into bacteria such as E.coli. The bacteria are subjected to very high temperatures which compel them to take up the DNA. This process is known as transformation. The plasmid contains an antibiotic resistance gene which helps them to survive in the presence of antibiotics. The plasmid-containing bacteria are selected on a nutrient containing antibiotics. The transformed bacteria survive, while the ones without a plasmid die.

Protein Production

The plasmid-containing bacteria are cultured, and the bacteria are provided with a chemical signal that helps them to target the protein. After protein production, the bacteria are split open to release it. The protein is purified, and the target protein is isolated from other contents of the cell.

The DNA molecules produced through the cloning techniques are used for many purposes, which include:

1. DNA cloning can be used to make proteins such as insulin with biomedical techniques.
2. It is used to develop recombinant versions of the non-functional gene to understand the functioning of the normal gene. This is applied in gene therapies also.
3. It helps to analyse the effect of mutation on a particular gene.

Also Read: Cloning Vectors

To know more about DNA cloning, its steps and its importance, keep visiting BYJU’S website or download BYJU’S app for further reference.

Also Read: Recombinant DNA Technology