This method of transformation is constituted of an accelerator (also called cannon) that I impelled metallic micron-projectiles (particles) loading DNA for inside of unbroken cells, fabrics or vegetal agencies, that later are regenerated (BESPALHOK F., et al WAR; OLIVEIRA, 2000). Some models of accelerators exist, but the most used currently they use the gas helium compressed to generate the necessary force for the particle acceleration (SANFORD et al., 1991). It enters the used archetypes more we have ‘ ‘ Biolistic? PDS 1000/He’ ‘ of the BioRad company who uses high helium pressures. The used metallic particles more in the bombardeamento are of tungsten and the gold. (BESPALHOK F., et al WAR; OLIVEIRAS, 2000) the particles are prepared with the precipitation of the DNA.

The used method more for DNA precipitation uses CCl2 and espermidina associated with tungsten particles. The transformation for bombardeamento occurs under vacuum, to increase the efficiency of penetration of particles (SANFORD et al., 1991). By this method several had been transformed species such as soy and maize. The bombardeamento of particles also has been used for the transformation of cloroplastos and mitocndrias (BESPALHOK F., et al WAR; OLIVEIRA, 2000). Markers of election are necessary to increase the transgnicas production of cells and plants.

An election marker allows the preferential growth of the cells transformed into the presence of the selective agent, preventing the growth of the cells not transformed. Genes that confer resistance the antibiotics or herbicidas can be used as marking of election. (BESPALHOK F., et al WAR; OLIVEIRA, 2000). Genes of resistance the herbicidas also have been used as frequently marking of election. It enters most used, we have the gene BAR that confers resistance to the herbicida Basta (fosfonotricina active principle or PPT) (BESPALHOK F., et al WAR; OLIVEIRA, 2000). For each protocol of transformation, it is necessary to determine the dose of the adjusted selective agent for the used species and cellular type.

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