Microprojectiles OR Biolistics OR Particle Gun for Gene Transfer - In recent years, it has been shown that DNA delivery to plant cells is also possible, when heavy microparticles (tungsten. or gold) coated with the DNA of interest are accelerated to a very high initial velocity (1,400 ft per, sec).

These microprojectiles, normally 1-3pm in diameter, are carried by a 'macroprojectile' or the 'bullet' and are accelerated into living plant cells (target cells can be pollen, cultured cells, cells in differentiated tissues and meristems) so that they can penetrate cell walls of intact tissue.

The acceleration is achieved either by an explosive charge (cordite explosion) or by using shock waves initiated by a high voltage electric discharge. The design of two particle guns used for acceleration of microprojectiles.