Gene Gun

The Biolistic Method

There are other methods of getting DNA into plant

cells besides injection by Agrobacterium

tumefaciens. For example, scientists

have used what is called a “gene gun” or

the “shotgun method” to transform

plants. This method, also called the

"biolistic method," was developed and

tested by John Sanford at Cornell

University in 1987. This method was

designed to simplify the complex process

of getting genes into a plant cell. Previous

methods utilized viruses or bacteria,

while this new method did not use any

suchorganisms. Much like in the previous

method, the genes of interest must be

both identified and isolated from the

original organism.

The DNA containing the desired gene, along with a

"marker gene" is mixed with several hundred small gold

or tungsten balls. These balls are loaded into the "gun"

and shot using air pressure at a plate of cells to be

transformed. While this isn't 100% effective all of the

time, some cells take up the desired genes and begin to

express them. The gene may be able to "slip" into the

genetic code of the cell and can be passed on through

the generations. This technique has been found to be

quite effective in plant engineering.

The cells that take up the genes can be identified with

the special "marker" gene. These plants will be grown

up for testing and possible eventual marketing. A

particularly successful strain may be cloned and

reproduced for many generations.