Final answer:
Gene therapy allows the introduction of foreign DNA into cells via methods including viral vectors, bacterial transformation, and direct injection. Viral vectors, like adenoviruses, are modified to carry genes for therapeutic purposes, and direct methods such as microinjection also serve to deliver DNA into cells.
Step-by-step explanation:
Gene Therapy Methods
Gene therapy can be used to introduce foreign DNA into cells by using viruses as vectors, through bacterial transformation, and solely by direct injection. Viral vectors are common carriers for introducing healthy genes into human patients with genetic diseases. Viruses like adenoviruses are modified to harbor the gene of interest and are then able to infect host cells to facilitate gene delivery. Other methods like microinjection, where DNA is injected directly into the nucleus of a cell, and bacterial transformation, where bacteria take up foreign DNA, are also utilized for transferring genes into cells.
The foreign DNA introduced can be of various origins, including viral, bacterial, plant, or animal. This serves multiple purposes from curing inheritable diseases to producing necessary proteins. In in vivo gene therapy, the gene is directly delivered into the cells of a particular tissue of the patient.