CRISPR-Cas9 is not the first method available to scientists for modifying DNA; it is by far, however, the easiest to use. With CRISPR-Cas9, the crRNA/tracrRNA sequence or an artificial guide RNA ...

Its primary component, the Cas9 enzyme (orange), cuts genomic DNA (blue). The enzyme is directed to its target--essentially any sequence along the genome--by hitching it to a strand of guide RNA ...

The Cas9 protein is the most widely used by scientists. This protein can easily be programmed to find and bind to almost any desired target sequence, simply by giving it a piece of RNA to guide it ...