CRISPR used for quick blood tests: E-CRISPR
Scientists from Case University (Cleveland, USA) used CRISPR system – type V, from Prevotella and Francisella bacteria – to detect viruses such as HPV and B19. They explained:
The CRISPR technique works so that it cuts all of the nonspecified single-strand DNA around it once the target is recognized, so we program to electrochemically probe this activity. No virus – no cutting, it’s that simple. And theo opposite is true: If CRISPR starts to cut, we know the virus is present.Yifan Dai
E-CRISPR relies on a methylene blue tag immobilized on a gold electrode. When the protein cleaves non-specific DNA, user measures high electrochemical current. In the opposite case – of specific cleavage – the current is low and, therefore, it confirms the presence of viral or other sequences of interest. Detection time ranged from 5 minutes to 3 hours.
New technology was also repurposed to detect proteins. Target-specific aptamer DNA can be measured whether it interacted with a protein interest and confirmed within 60 minutes of measurement.
E-CRISPR, although preliminary, is yet another demonstration of CRISPR-based detection capabilities. Previously, scientists have developed – also with Cas12a – paper strips for detecting Dengue and Zika viruses (more).
Publication: Dai, Y., Somoza, R. A., Wang, L., Welter, J. F., Li, Y., Caplan, A. I., & Liu, C. C. (2019). Exploring the Trans-Cleavage Activity of CRISPR Cas12a (cpf1) for the Development of a Universal Electrochemical Biosensor. Angewandte Chemie International Edition. doi:10.1002/anie.201910772