CRISPR pioneers and competitors Jennifer Doudna and Feng Zhang are once again locked in a CRISPR race, this time to show how CRISPR—the technology best known for its gene-editing prowess—can also be harnessed to develop a sensitive diagnostic.
Today, two research groups, one led by Doudna of the University of California, Berkeley, the other by Zhang of the Broad Institute, published papers in the journal Science, each describing its own method of using a CRISPR-based system to detect tiny amounts of genetic material from viruses or tumors in human samples. The research teams are also competing to come up with the most clever name for their tests. (And their respective institutions have famously been battling over the last three years over patents covering CRISPR-Cas9 gene editing.)
The CRISPR gene-editing technology that companies like Editas Medicine (NASDAQ:EDIT) (co-founded by Zhang), Intellia Therapeutics (NASDAQ:NTLA) (co-founded by Doudna), and CRISPR Therapeutics (NASDAQ:CRSP) are moving into human clinical trials uses the DNA-snipping Cas9 enzyme to edit genomes. But researchers have found several other editing enzymes that behave differently in a variety of ways.
These other enzymes are at the heart of the new diagnostic tools. Doudna’s DETECTR system relies on a Cas12a enzyme instead of Cas9. Doudna’s team showed that it could program its system to accurately detect DNA from two cancer-causing types of the human papillomavirus (HPV) from human samples.
Zhang’s SHERLOCK system uses Cas12a and Cas13 enzymes, and is designed to sniff out RNA molecules from the dengue and Zika viruses, as well as specific lung cancer mutations in DNA from human blood samples. Zhang’s team incorporated its technology into thin paper strips (pictured above; negative test results shown in middle strips; positive, right) that could be used in a similar way as a pregnancy test.