Its relevance to biomedicine and genome editing comes from the fact that scientists can engineer it to deliberately modify the genetic material of an organism. This is done with the help of Cas9, an endonuclease enzyme that is capable of creating precise cuts in the cell’s DNA. Cas9 is important because breaks in DNA need to be made in highly specific locations so that the structural integrity of the cell remains stable enough for it to be automatically repaired afterwards via non-homologous end joining or, more frequently, homology directed repair (Redman, A. King, Watson, D. King, 2016). Cas9 is paired with guide RNA that specifies where the cut should occur, as well as a chunk of DNA that should be used by the cell as a template for when it tries to repair itself. The CRISPR-Cas9 system is then transfected into the cell, where it searches for RNA that matches that of its guide RNA, creates a break at that location, and then allows the break to be filled by the genetic material that was inserted into the sequence. By selectively modifying the parts of the system, we are able to not only selectively disable specific genes and then observe the effect that it has on the cell, but also insert new genes into an organism that does not already contain …show more content…
Many wonderful discoveries have been made in the field using a multitude of plants and animals, but very little of it has been applied to humans due to ethics codes and the high potential for negative side effects caused by unforeseen mutations. The precision that the CRISPR-Cas9 system provides is such a monumental improvement over previous methods of genetic engineering that it was able to be tested in a clinical trial involving a patient with lung cancer as early as 2016, only a few years after the system was initially applied to human genome editing (Cyranoski, 2016). The speed at which the technology is being tested and improved, its inherently low cost of production, and the potential of the system itself makes it one of the most important breakthroughs in the history of biomedicine. CRISPR-Cas9 could prove instrumental in the discovery of cures for diseases and disorders that arise as a result of mutations in the DNA, such as sickle cell disease and beta thalassemia. Treating them could be as simple as identifying which gene on which chromosome has mutated – information that is already known, in many cases – and fashioning a CRISPR-Cas9 system that targets that gene and replaces it with a healthy, unmutated variant. Of course, miscalculations are always an important possibility to consider, and an error leading to an incorrect gene being