A technique for introducing genetic material into living cells, especially plant cells, in which DNA-coated microscopic particles are fired into the cell using a special gun. The microprojectiles, typically gold particles of diameter 0.5 to 1 μ‎m, are accelerated to high velocity by a specially modified small-calibre gun and penetrate the cell walls and plasma membrane with minimal damage. Hence novel DNA can be inserted into intact plant cells (see genetically modified organisms). The technique can also be used for delivering DNA through the double membranes of intact chloroplasts and mitochondria.