Feng Zhang, Jonathan S. Gootenberg and colleagues have created a version of CRISPR-Cas that can be used to diagnose infections with high sensitivity.
Existing methods include detecting genetic sequences and present limitations such as sensitivity, specificity, simplicity, cost and speed. This new system, dubbed SHERLOCK, exploits RNA. Binding the target RNA activates this particular Cas enzyme to cleave nearby a reporter RNA which releases a fluorescent signal when it is cleaved. They also used recombinase polymerase amplification to further boost sensitivity of the system. The system can detect low titers of Zika virus in serum, urine and saliva and can be used to measure viral load.
It was also effective at identifying various bacterial strains, even differentiating between strains of bacterial pneumonia with different resistance mutations, and demonstrated potential to detect cancer mutations. The test can be redesigned and synthesised in a few days for as low as $0.61/test, thus opening up new avenues for the rapid and sensitive detection of biological molecules.