Category: News

An on-going challenge with COVID-19, which has huge implications for future pandemics, is the rapid emergence of viral variants that makes diagnostic tools less accurate, calling for rapid identifications of recognition elements for detecting new variants caused by mutations.

We hypothesize that we can fight mutations of the viruses with mutations of existing recognition elements. We demonstrate this concept via rapidly evolving an existing DNA aptamer originally selected with the spike protein (S-protein) of wildtype SARS-CoV-2 for enhanced recognition of the same protein of the Omicron variants.

The new aptamer has acquired 22 mutations within its 40-nucleotide core sequence and improved its binding affinity for the S-proteins of diverse Omicron subvariants by > 100-fold compared to its parental aptamer.

The aptamer was implemented into an enzyme-linked aptamer binding assay (ELABA), which was applied for detecting Omicron variants in the saliva of infected patients. The assay produced a sensitivity of 86.5% and a specificity of 100%, which was established with 83 clinical samples

Check out the full paper HERE.

Through the hard work of some incredible people, we have managed to implement our MSA52 aptamer into an electrochemical biosensor.

In this paper, we show that real-time kinetic profiling of the aptamer binding with its antigen can yield high-precision viral detection.

Check out the full paper HERE.

Functional nucleic acid-based diagnostics and therapeutics targeting viral genomic RNA must be able to overcome extensive RNA secondary and tertiary structures in order to be effective. This paper demonstrates a new method to improve the accessibility of  RNA-cleaving DNAzymes (10-23) to relatively inaccessible target sites within large, structured RNA molecules from SARS-CoV-2, using antisense DNA oligonucleotides (ASOs) that flank the DNAzyme target site.

We show that this method can be used to improve the accessibility and activity of 10-23 to previously inaccessible target sites by as much as 2000-fold. We also use an ASO screening approach to demonstrate that structured regions within large RNA molecules typically exist near the target site, rather than more distal regions.

Overall this method is a cheap, fast and effective way to improve DNAzyme accessibility to inaccessible target sites within any large RNA molecule.

Check out the full paper HERE.

A recent MSc graduate student of our lab got his research published!

Jake’s project focused on looking at the evolution of the hammerhead ribozyme through a in vitro selection lens.

The ‘essential’ nucleotides within the catalytic core may not be as essential as initially thought…

Check out the full paper HERE.

A paper got published recently in which we show that dimers and trimers constructed from monomeric aptamers can enable more accurate detection of pathogens when using a Litmus test.

Check out the full paper HERE.

Read about our latest RNA-cleaving DNAzyme, one that requires an organic solvent to function!  

Given that many organic molecules are widely used as solvents in synthetic and analytical chemistry, we were motivated to derive a functional DNAzyme in these conditions. While several DNAzymes in literature have been reported to work under organic conditions, no prior study has ever selected for DNAzymes that strictly require an organic solvent to function.  

In this study, using a positive selection in dimethyl sulfoxide (DMSO) and a negative selection in an aqueous solution, we isolated an RNA-cleaving DNAzyme that strictly requires DMSO for its catalytic activity. A minimized, more efficient version of the DNAzyme was then generated, and applied in a proof-of-concept aptazyme system for sensing applications.  

Overall, we continue to be fascinated by the amazing capabilities of in vitro selection and catalytic DNA! Check out the full paper HERE.

A research article first published in February 2023 on the characterization of diverse DNA aptamers for recognition of COVID-19 has been featured on the cover of the most recent issue (issue #5) of the journal Analysis & Sensing.

We’re all very excited and overjoyed with the recognition of all the hard work that’s being done here in the lab.

For the full article, check out the following link:

Comparative Characterization of Diverse DNA Aptamers for Recognition of Spike Proteins of Multiple SARS-CoV-2 Variants

For more papers, see the Publications page of the website.