Particle bombardment is a technique which can be used to introduce foreign DNA to a cell culture. There are several methods of particle bombardment available, most involving the use of a “gene gun,” a device which is designed to deliver particles into a cell culture reliably and efficiently. This technique is used in labs all over the world for research and development purposes, with the use of specialized equipment, some of which is customized for specific applications.
In particle bombardment, particles, often of heavy metals, are used to breach the cell wall. If the particles are coated in DNA, the foreign DNA will be introduced to the cell through the breaks in the cell wall. If the cell walls are suspended in a solution of DNA, some will be picked up by the particles as they move through the solution, forcing the DNA into the cell. In either case, foreign DNA which has been customized for the organism being researched is essentially injected into the cells.
The earliest uses of particle bombardment were in the development of transgenic crops. Using this technique, researchers could do things like introducing genes for herbicide resistance to cell cultures which would later be used to develop crops. Other genetic modifications could be introduced as well. Gradually, the use of the technique expanded to cultures of bacteria and animal cells, as researchers refined particle bombardment.
This technique does require some finesse on the part of the technician performing it. The particles must be carefully chosen and delivered in a controlled fashion. The goal is to introduce the particles with minimal damage to the cells, so that they can recover after the particle bombardment and continue growing and dividing. If the cells are too damaged, they will die off. On the other hand, if the particle bombardment is not fully delivered, some of the cells in a culture will not absorb the foreign DNA.
Researchers also need to make sure that they are introducing the appropriate DNA to their target cells culture. If the DNA strands being inserted are not well matched to the organism, the particle bombardment may fail because they cannot be integrated into the organism, or because errors occur. This requires knowledge of genetics and a familiarity with the genome of the organism being studied to confirm that the DNA will end up where it is supposed to, and that it will function as intended by the researchers.