Scientists create rapid diagnostic technology to detect SARS-CoV-2
Combining experts in molecular genetics, chemistry and the health sciences, researchers at the University of California at San Diego have created rapid diagnostic technology that detects SARS-CoV-2, the coronavirus that causes COVID-19.
The new SENSR (sensitive enzymatic nucleic acid sequence reporter), described in an article published in the journal ACS sensors, is based on CRISPR gene editing technology which enables rapid detection of pathogens by identifying genetic sequences in their DNA or RNA.
Currently, many human pathogens are detected using a method known as real-time polymerase chain reaction. Although very precise and sensitive, these diagnoses are time consuming and require specialized laboratory equipment, which limits their use to healthcare and specialized establishments. SENSR is designed to simplify the process of detecting SARS-CoV-2 for possible adaptation for home use.
While the Cas9 enzyme has been widely used in CRISPR genetic engineering research, scientists have recently used other enzymes such as Cas12a and Cas13a for the development of very accurate CRISPR-based diagnostics. Developed in the same vein, SENSR is the first diagnosis of SARS-CoV-2 to exploit the enzyme Cas13d (in particular a ribonuclease effector called “CasRx”).
The researchers believe that in order to maximize the capabilities of CRISPR and extend the genetic diagnostics pipeline, all Cas enzymes that can complement or complement existing systems should be explored.
CRISPR has dramatically improved our capabilities to quickly identify infected people and offer point-of-care testing in low-resource environments, which was not possible before. SENSR further opens the toolbox for CRISPR diagnostic systems and will help detect emerging pathogens before they become pandemics. “
Omar Akbari, lead author of the study, professor of biological sciences, UC San Diego
In developing SENSR, Akbari’s Molecular Genetics Laboratory worked in collaboration with the laboratory of Professor Elizabeth Komives of the Department of Chemistry and Biochemistry (Division of Physical Sciences) to purify SENSR proteins and the laboratory of Rob Knight of the Department of pediatrics (School of Medicine and Microbiome Innovation Center) to test SARS-CoV-2 samples.
SENSR is one of the latest developments in UC San Diego’s innovative approach to tackling the COVID-19 pandemic. The university’s scientifically recognized return to learning strategy for campus safety includes Knight’s groundbreaking wastewater screening program which has resulted in the early detection of 85% of COVID-19 cases on campus. With nearly 10,000 students on campus in the current academic year, the Return to Learn program strategy, which includes high vaccination rates, has led to a COVID-19 case rate of less than 1% , becoming a model for other academic institutions.
The first tests of the development of SENSR demonstrated the detection of SARS-CoV-2 in less than an hour. The researchers note in the article that further development is needed, but the technology has the potential to become “powerful molecular diagnostics with many applications.”
Ultimately, Akbari envisions SENSR becoming important in places such as airports so that passengers can quickly determine if they are carriers of a virus.
“We must continue to innovate in the field of detection and protection to offer more tools. Thus, in the event of a new pandemic, we will have scalable diagnostic systems at the point of care for rapid distribution”, Akbari said.
The article published in ACS sensors brought together a mix of UC San Diego graduate students, postdoctoral fellows, project scientists, and faculty members. They include: Daniel Brogan, Duverney Chaverra-Rodriguez, Calvin Lin, Andrea Smidler, Ting Yang, Lenissa Alcantara, Junru Liu, Robyn Raban, Pedro Belda-Ferre, Rob Knight, Elizabeth Komives and Omar Akbari. Igor Antoshechkin of CalTech is also a co-author.
Research funding was provided by: UC San Diego seed funds for emerging research related to COVID-19; a Directors New Innovator Award from the National Institutes of Health / National Institute of Allergy and Infectious Diseases (NIH / NIAID) (DP2 AI152071-01 and R21 (1R21AI149161); a grant from the DARPA Safe Genes Program (HR0011-17- 2-0047); a Director’s Pioneer Award from the National Center for Complementary and Integrative Health (DP1 AT010885); the NIH Molecular Biophysics Training Fellowship (T32 GM00832); the Return to Learn program from UC San Diego via the laboratory EXCITE (EXpedited COVID-19 Identification Environment); and Molecular Biophysics Training Grant, NIH Grant (T32 GM00832).