We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
Technopath Clinical Diagnostics - An LGC Company

Download Mobile App





CRISPR-Powered COVID-19 Test Detects SARS-CoV-2 in 30 Minutes Using Gene Scissors

By LabMedica International staff writers
Posted on 29 Nov 2022
Print article
Image: The multiplex chip can measure the viral load in a nasal swab (Photo courtesy of University of Freiburg)
Image: The multiplex chip can measure the viral load in a nasal swab (Photo courtesy of University of Freiburg)

CRISPR-Cas is versatile: Besides the controversial genetically modified organisms (GMOs), created through gene editing, various new scientific studies use different orthologues of the effector protein ‘Cas’ to detect nucleic acids such as DNA or RNA. Now, a group of researchers has introduced a microfluidic multiplexed chip for the simultaneous measurement of the viral load in nasal swabs and (if applicable) the blood antibiotic levels of COVID-19 patients. The biosensor for the nucleic acid amplification-free detection of SARS-CoV-2 RNA was developed by researchers at University of Freiburg (Baden-Württemberg, Germany).

The market launch of rapid antigen test kits has significantly changed the way in which society handles the effects of the pandemic: Individuals suspecting an infection with SARS-CoV-2 can now test themselves at home with kits that are readily available at most drug stores, pharmacies and supermarkets, instead of making an, oftentimes difficult to acquire, appointment for PCR testing, that requires one to three additional days to receive the result. This convenience is, however, paid for with test sensitivity. This issue became flagrantly apparent during the wave of infections last winter, when the ‘lateral flow devices’ frequently failed to detect infections with the Omicron-variant until after the onset of symptoms.

One alternative is a CRISPR-powered COVID-19 test. Similar to the rapid tests performed at home or in testing centers, a nasal or oral swab sample solution is added to a reaction mix. In contrast to these viral antigen tests, however, CRISPR, like rt-qPCR, screens the patient sample for RNA sequences characteristic to SARS-CoV-2. If the sample contains the RNA snippet of interest, the effector protein (Cas13a) is activated and cleaves the reporter RNA provided within the reaction mix. The absence of intact reporter creates an inversely proportional relation to the abundance of viral RNA within the sample, that is then analyzed in an electrochemical readout (low current densities indicate a high viral load).

In light of recent decisions of several federal states to discontinue isolation requirements for individuals tested positive for COVID-19 reliable, sensitive and rapid testing opportunities will again gain significance within the task of adequately managing recurring waves of infections. The latter will also inevitably coincide with the hospitalization of patients with severe symptoms and disease progressions. This is where another feature of the microfluidic chip comes into play: the combination of the CRISPR-assays with a ß-lactam antibiotic detection. COVID-19 patients often acquire bacterial co-infections that are then treated with broad-spectrum antibiotics like amoxicillin, ampicillin or piperacillin. Finding and maintaining the correct and personalized dosage is hereby crucial in guaranteeing a successful treatment as well as in reducing the emergence of resistant strains. The proposed sensor could facilitate dealing with these issues, through simultaneous monitoring of the viral load and blood antibiotic levels.

“The trade-off between sensitivity and sample-to-result time could potentially be bridged using our method,” said Midori Johnston, first author of the study.

“Our system herein omits nucleic acid amplification and is flexibly adaptable to new, clinically relevant mutations of the virus while exclusively employing inexpensive, shelf stable and non-toxic reagents as well as a portable measurement setup,” explained microsystems engineer Dr. Can Dincer of the Department of Microsystems Engineering, University of Freiburg who headed the research group.

Related Links:
University of Freiburg

Gold Supplier
SARS-CoV-2 RT PCR Kit
SARS-CoV-2 Variant Lambda (C.37) Real Time PCR Kit (RUO)
New
Reagent Strips
Uriquest Plus I
New
3-Part Diff Hematology Analyzer
Aquarius 3
New
POCT Analyzer

Print article
MEDLAB - INFORMA

Channels

Molecular Diagnostics

view channel
Image: A novel research study moves the needle on predicting sudden cardiac arrest (Photo courtesy of Pexels)

Newly Identified Protein Biomarkers in Blood Predict Sudden Cardiac Arrest Before it Strikes

Sudden cardiac arrest, or the sudden loss of heartbeat, is a life-threatening heart condition and often fatal. Despite providing an organized emergency medical response, less than 10% of individuals having... Read more

Immunology

view channel
Image: Histopathology of Langerhans cell histiocytosis: The variation in nuclear contours of these cells is evident in this lesion. Classic `kidney bean` nuclei of Langerhans cells with a central groove are present (Photo courtesy of John Lazarchick, MD)

Cooperativity Between Myeloid Lineages Promotes Langerhans Cell Histiocytosis Pathology

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia seen in children and adults who present with lesions composed of pathologic variants of myeloid cells that share certain phenotypic... Read more

Microbiology

view channel
Image: Medical illustration of Carbapenem-resistant Enterobacteriacea (Photo courtesy of CDC, Stephanie Rossow)

Breakthrough Test Enables Targeted Antibiotic Therapy for Various Enterobacter Species

Bacteria of the Enterobacter genus are considered to be the most dangerous bacteria linked to hospital infections across the world. Some of their representatives demonstrate high resistance to commonly-used... Read more

Technology

view channel
Image: Flexible copper sensor made cheaply from ordinary materials (Photo courtesy of University of São Paulo)

Low-Cost Portable Sensor Detects Heavy Metals in Sweat

Heavy metals like lead and cadmium can be found in batteries, cosmetics, food and many other things that have become a part of daily life. However, they become toxic if they accumulate in the human body... Read more
Copyright © 2000-2023 Globetech Media. All rights reserved.