US-based researchers from Broad Institute have developed a technique that can be used to update the CRISPR-based Sherlock diagnostic platform to rapidly identify viruses directly in bodily fluids such as blood and saliva.
This HUDSON technique is intended to eliminate the need for a lab environment and trained personnel to extract nucleic acids from samples. It is intended to be useful during outbreaks and pandemics in regions lacking access to laboratories and medical staff.
HUDSON involves a rapid chemical and heat treatment of patient samples to inactivate some enzymes that degrade the genetic targets.
When tested on saliva and blood serum, the combination of HUDSON and SHERLOCK demonstrated direct identification of Dengue virus. It also detected Zika virus particles in blood and urine samples.
Harvard graduate student and lead researcher Catherine Freije said: “With this new assay, a patient can give a single blood or urine sample, it can be analysed in just a few reactions to determine which virus it contains, and then that patient can get started on the right treatment.”
Researchers added a feature for SHERLOCK to differentiate related viral species and to identify clinically relevant mutations, including small variations in Zika virus that has been found in microcephaly.
Broad Institute member Pardis Sabeti said: “Rapid and sensitive tools are critical for diagnosing, surveilling and characterising an infection. We’ve taken the SHERLOCK technology and optimised it in the context of these very applied biological scenarios.”
The team is planning to test SHERLOCK in Nigeria, which recently suffered an unusual surge in Lassa fever. As this disease requires early intervention, an accurate and fast diagnosis is considered critical.
Furthermore, they are developing a framework to enable easy access to the SHERLOCK platform during outbreaks.