Gene editing tool Sherlock

Researchers have developed a diagnostic platform based on the gene editing tool CRISPR, which could one day be used to respond to viral and bacterial outbreaks, monitor antibiotic resistance, and detect cancer. The researchers adapted a CRISPR protein that targets RNA as a rapid, inexpensive, highly sensitive diagnostic tool.

The new tool, dubbed SHERLOCK (Specific High-sensitivity Enzymatic Reporter unLOCKing), can be designed for use as a paper-based test that does not require refrigeration. It is well suited for fast deployment and widespread use inside and outside of traditional settings — such as at a field hospital during an outbreak or a rural clinic with limited access to advanced equipment, the researchers said. CRISPR-Cas9 is a new technology that scientists to edit parts of the genome by removing, adding or altering sections of the DNA sequence.

Far to the right side of the decimal point—beyond milli, micro, nano, pico, and femto—lives the atto, the metric prefix representing 10-18. Slap it in front of a unit of concentration, such as molar, and it means that something exists in an extraordinarily small amount—think one part per quintillion. That’s the realm of SHERLOCK, a new diagnostic system that can detect attomolar levels of viruses in a sample and also distinguish Zika from its close relative, dengue.

This exquisitely sensitive and specific tool promises to help detect diseases that other diagnostics miss, and it’s simple and cheap to use. Earlier efforts at making a viral detector became overshadowed by CRISPR’s wild success at editing genomes. In a study published in the journal Science, the researchers described how this RNA-targetting CRISPR enzyme, Cas13a, was harnessed as a highly sensitive detector able to indicate the presence of as little as a single molecule of a target RNA or DNA molecule.

The scientists demonstrated the method’s versatility on a range of applications, including detecting the presence of Zika virus in patient blood or urine samples within hours, and rapidly reading human genetic information, such as risk of heart disease, from a saliva sample.