GENETICS RESEARCH. GENETICS RESEARCH Gene therapy requires a gene-drug and a vector to carry it to the target cell. The study of how these vectors transfer the gene-drug to the target site is termed vectorology. Here the efficacy of the gene transfer is being studied under fluorescence microscopy. Fluorescence In Situ Hybridization (FISH) is used to localize the position of the gene on the chromosome. Here the chromosome is visualized before and after gene therapy. Before, the genes are seen