Which of these is not a method for introducing genes into a cell?

Methods for introducing genes into a cell include, transfection (chemical based), electroporation (physical), infection (viral mediated) and recombination techniques. Fluorescence in situ hybridization (FISH) is a cytogenetic technique that uses fluorescence-tagged probes to detect specific DNA sequences in tissue samples. It is not used for introducing genes into the cells. Methods for genetic manipulation: Transfection is the most commonly used method for introducing transgenes into human embryonic stem (hES) cells. This system is based on the use of carrier molecules that bind to foreign nucleic acids and introduce them into the cells through the plasma membrane. Electroporation is a method that employs the administration of sho electrical impulses that create transient pores in the cell membrane, allowing foreign DNA to enter into the cells. Infection is gene manipulation by viral infection which can produce a very high percentage of modified cells. Advantage over other systems are, high efficiency of DNA transfer (almost 100% efficiency) and single copy integrations. Recombination occurs by physical exchange of DNA. An endogenous gene can be replaced by a transfected gene using homologous recombination. Recombination is the result of crossing-over that occurs at chiasmata and involves two of the four chromatids. Ref: Human Embryonic Stem Cell Protocols By Kursad Turksen, 2006, Page 225