CAMBRIDGE, MASSACHUSETTS — Scientists from Harvard University and the Massachusetts Institute of Technology have developed a new method of editing DNA, called prime editing, which combines CRISPR-Cas9 with a reverse transcriptase enzyme.<br /><br />The CRISPR-Cas9 is used to nick one DNA strand, while the enzyme generates a new DNA strand which is inserted into the original DNA strand, according to a study published in the journal Nature. <br /><br />Another reverse transcriptase enzyme then guides the CRISPR-Cas9 to nick the other DNA strand. The strand is repaired as the enzyme replicates gene edits over from the new DNA strand, producing a fully editing DNA strand.<br /><br />According to a Harvard news release, prime editing can also be used to replace one DNA letter with another and could correct up to 89 percent of genetic mutations."<br /><br />In the study, researchers explained that they used prime editing to make more than 175 edits in human cells in a laboratory and successfully corrected sickle cell anemia and Tay-Sachs disease.<br /><br />CRISPR-Cas9 if used by itself isn't as precise as prime editing and could lead to mismatched DNA strands that either include extra DNA code or are missing a certain genetic code, according to the Harvard news release. <br /><br />The authors of the study concluded by saying they will investigate the effects of prime editing on human cells and will continue to test prime editing on cells.
