What is 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 Steps
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.
The plasmid containing the 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.
Importance of DNA Cloning
The DNA molecules produced through the cloning techniques are used for many purposes which include:
- DNA cloning can be used to make proteins such as insulin with biomedical techniques.
- 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.
- 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 importance, keep visiting BYJU’S website or download BYJU’S app for further reference.
Frequently Asked Questions
What is the purpose of DNA cloning?
DNA cloning is used to create a large number of copies of genes or a DNA segment.
Name the first clone.
Dolly, a female sheep, was the first mammal to be cloned from adult somatic cells by the process of nuclear transfer.
Name the first monkey that was cloned.
Tetra was the first rhesus macaque created by embryo splitting.
What all animals have been cloned?
Cat, deer, ox, mule, dog, rabbit and rat are the animals that have been cloned.
Also Read: Recombinant DNA Technology