The complementary ends pair and the enzyme DNA ligase is used to join them together. The plasmid is then introduced into the E. coli cells by transformation. The E. coli cells that take-up the new plasmid then can be identified by their resistance to the antibiotics kanamycin and neomycin. The E. coli replicates the plasmids so that a single cell may contain hundreds of identical copies. After the plasmids containing the Bt gene have been multiplied the Bt toxin gene is then isolated again and is inserted into a plasmid of the bacterium Agro bacterium tumafacien using the same techniques as used to insert the Bt gene into the E. coli. This plasmid is then put back in the Agro bacterium, which transfers the Bt gene into the cotton plant cell. The bacteria does this by infecting the plant cell causing a tumor to form and while infecting the plant part of the plasmid is transferred into the plant's nucleus. .
The transgenic cotton plant produced by this genetic technique has an altered genotype, which leads to it having an altered phenotype. The plant can then produce the Bt Toxin in its leaves through protein synthesis. This then crystallizes and when an insect eats the protein it reacts in the insect's gut and kills the insect within 24 hours. This altered genotype and phenotype will increase the chances of survival of the cotton plants against the cotton budworm (Helicoverpa) and the native budworm (H. puntigera). The protein produced by the plant is only toxic to these pests and will only be activated in the gut of these pests. The gene shouldn't transfer into other plants that are related to cotton or disturb natural ecological systems. It is possible, however, that the gene may enter a wild strain of cotton may and this would increase the survival chances of the cotton in the wild. Research has a promising futures but some obstacles might find there way into the progress of biotechnology.