For entry of foreign DNA into host cells there are other methods also. For example, in the microinjection method, recombinant DNA is injected directly into the nucleus of the animal cell. Another method that is useful for plants is to bombard cells with high-velocity particles of gold or tungsten coated with DNA, called biolistics or gene gun. The last method in which harmless pathogen vectors are used. When these vectors are allowed to infect cells, they transfer recombinant DNA into the host.