Gene Cloning- Requirements, Principle, Steps, Applications


DNA (deoxyribonucleic acid) is the molecule that carries the genetic information of all living organisms. DNA is composed of four types of nucleotides: adenine (A), thymine (T), cytosine (C) and guanine (G). These nucleotides form a double helix structure, where each strand is complementary to the other. The sequence of nucleotides in a DNA molecule determines the sequence of amino acids in a protein, which in turn determines the structure and function of the protein.

Gene cloning is a technique that allows scientists to produce multiple copies of a specific gene or a segment of DNA. Gene cloning can be used for various purposes, such as studying gene function, producing recombinant proteins, creating transgenic organisms, developing gene therapies, etc. Gene cloning involves the following steps:

  • Isolation of the DNA fragment or gene of interest from a source organism
  • Insertion of the DNA fragment or gene into a suitable vector, which is a DNA molecule that can replicate independently in a host cell
  • Introduction of the vector containing the DNA fragment or gene into a host cell, usually a bacterium or a yeast
  • Selection and identification of the host cells that have taken up the vector and contain the DNA fragment or gene
  • Multiplication and expression of the DNA fragment or gene in the host cells
  • Isolation and purification of the product, which can be either the DNA fragment or gene itself or the protein encoded by it

Gene cloning can be classified into two types: cell-based and cell-free. Cell-based gene cloning involves the use of living cells as hosts for the vectors and the DNA fragments or genes. Cell-free gene cloning involves the use of artificial systems that mimic the cellular environment and allow the synthesis of DNA fragments or genes without using living cells. In this article, we will focus on cell-based gene cloning and its requirements, principle, steps and applications.