Gene Cloning Techniques

The science of genetics seeks to explain the mechanisms of inheritance and evolution as well as lmany other practical problems. Transferring genes between organisms offers many exciting prospects. Scientists now have the ability to take individual genes and create multiple copies of them; this is called gene cloning.

Mechanism

Genes can be multiplied in a test-tube, but it is often much easier to put the gene or DNA fragment into other organisms like bacteria which will then adopt the new DNA as their own and copy it for you.

Using vectors to transfer genes

Human genes are often transferred into bacteria or yeast because these microorganisms multiply quickly. In bacteria they form a huge population which expresses the gene and creates large quantities of the gene product.

Microprojectiles

Microprojectile refers to shooting DNA fragment into host cells. Remarkably, some of the cells recover and accept the foreign DNA.

Electroporation

Electroporation technique involves exposing the host cells to rapid, brief bursts of electricity which create temporary gaps in the cell surface through which foreign DNA can enter.

Liposomes

Liposome (i.e. artificial vesicle) is a preferred method of smuggling DNA into cells. DNA is inserted into Liposomes. The Liposomes fuse with the surface membrane of the host cell and introduce the DNA into the cytoplasm.

Calcium phosphate precipitation

Plasmids are mixed with calcium phosphate. As the calcium phosphate precipitates, grains are formed that contain DNA. These grains can enter the cells by endocytosis (i.e. incorporation of substances into a cell).

References

• Gene cloning and DNA analysis: an introduction‎; Terence A. Brown, 2006
• Molecular neurobiological techniques; Alan A. Boulton, Glen B. Baker, Anthony T. Campagnoni, 1990