Why might a laboratory worker attempting to diagnose a genetic disorder prefer to work with photographs of chromosomes rather than the chromosomes themselves

Gene therapy is the process by which human beings manipulate genes for use in practical tasks. In examining a genetic disease in humans, gene cloning has to take place. A gene from the human being with the disorder is extracted from a plasmid cell and inserted into a bacterial cell. Culturing is done and finally the multiplied genes are used for study. The bacterial cell is used in the first part of the research and examination but upon getting a hypothetic cure, the characteristic of the disease and maybe the eradication be tested in higher organisms. The reason why the whole process is time consuming is because it is scientific. One has to verify and prove results severally before making viable conclusions.