Paper- based DNA test can rapidly diagnose diseases

Boston, Feb. 19: Scientists have developed the first inexpensive, miniature paper test that can precisely detect diseases from DNA samples and allows the results to be seen with the naked eye, just like pregnancy tests.

After dipping the paper strip into a processed sample, a line appears, indicating whether the target molecule was detected or not.

The test can accurately quantify the amount of target in a sample and test for multiple targets at once. The innovations build on the team’s earlier version of SHERLOCK ( Specific High Sensitivity Reporter unLOCKing) and add to a growing field of research that harnesses CRISPR systems for uses beyond gene editing.

“SHERLOCK provides an inexpensive, easy- touse, and sensitive diagnostic method for detecting nucleic acid material — and that can mean a virus, tumour DNA, and many other targets,” said Feng Zhang, professor at Massachusetts Institute of Technology ( MIT) in the US.

“The SHERLOCK improvements now give us even more diagnostic information and put us closer to a tool that can be deployed in realworld applications,” said Zhang, senior author of the study published in the journal Science.

The researchers, including those from Harvard University in the US, previously showcased SHERLOCK’s utility for a range of applications. The team used SHERLOCK to detect cell- free tumour DNA in blood samples from lung cancer patients and to detect synthetic Zika and Dengue virus simultaneously, in addition to other demonstrations.

“The new paper readout for SHERLOCK lets you see whether your target was present in the sample, without instrumentation,” said Jonathan Gootenberg, a Harvard graduate student in Zhang’s lab.