Overheads to describe these 3 methods. Electroporation of animal cells is very similar to the procedure used for plant cells. Animal cells and DNA are mixed together and then subjected to an electric shock. It is believed that the electric shock produces small temporary pores in the membrane that allow DNA to enter the cell. At least some of the DNA can travel to the nucleus.
Liposomes are artificial membranes that can be formed in a test tube.
DNA can be mixed with the liposome preparation under the appropriate conditions. This results in the encapsulation of DNA into synthetic lipid membranes. When this membrane fuses with the cell plasmamembrane, DNA is released into the cell and somehow ends up in the nucleus. Calcium phosphate precipitates of DNA form when DNA is mixed with calcium chloride. When these DNA precipitates are added to animal cells growing in culture, the precipitated DNA can be taken up by the cells, again transferred to the nucleus and expressed.