This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
Methods of introducing gene in target cells are all except 
Select and explain. 
A. Electroporation, B. Transfection, C. Site directed recombination, D. FISH
D: FISH
Answer: D: FISH 
Explanation: Fluorescence in situ hybridization(FISH) is a cytogenetic technique that uses fluorescent probes that bind to only those pas of the chromosome with a high degree of sequence complementarity.