Take a look at this recent publication from the Li Lab in Angewandte Chemie International Edition. In this paper, we explore a novel signal amplification strategy termed DNAzyme feedback amplification (DFA). This method takes advantage of rolling circle amplification and RNA-cleaving DNAzymes for biosensing applications, with sensitivity improvements of 3-6 orders of magnitude when compared to conventional methods. -Suraj
Author: Jim
Detection of DNA Amplicons of Polymerase Chain Reaction Using Litmus Test
Checkout this recent paper from the Li Lab in Scientific Reports, “Detection of DNA Amplicons of Polymerase Chain Reaction Using Litmus Test.” Here we report on a novel DNA detection method that combines the advantages of the polymerase chain reaction with the simplicity of a litmus test. The diagnostic capabilities of the platform is demonstrated using clinically validated stool samples from C.difficile infected patients. -Suraj
Li Lab Places 3rd in the Biochemistry Halloween Costume Contest
Yingfu as the “Crazy Cat Lady” and his gang of cats
Funding for Legionella Biosensors Brings Research and Industry Together
Funding was recently announced to advance the Li lab’s research into rapid Legionella diagnostic technologies. Congratulations to our McMaster collaborators Dr. Carlos Filipe and Dr. John Brennan of the Biointerfaces Institute and industry partners TGWT Clean Technologies Inc., Cytodiagnostics and Mold and Bacterial Consulting Labs. Read more about it on the McMaster News website.
Programming a topologically constrained DNA nanostructure into a sensor
Checkout the Li Lab’s latest paper in Nature Communications! In a collaborative project between the Li Lab and McMaster’s Biointerfaces Institute, we report a novel reporter system based on mechanically interlocked circular DNA, rolling circle amplification and DNAzymes for highly sensitive bacterial detection.
C.difficile Detection
Read about a new highly specific Clostridium difficile catalytic DNA biosensor in the Li Lab’s latest publication in Angewandte Chemie International Edition. You can also checkout the a profile of the report on the McMaster Daily News.
A Busy Week of Holiday Festivities
The Li Lab came together to participate in the departmental ginger bread house contest, coming up with a 2 part winter wonderland gingerbread house and Eiffel tower. Congrats to us on winning 1st place! Check out the rest of the details at the BBS Facebook Page.
Everyone also came out to the annual Li Lab Christmas lunch.
Finally, our 2nd annual Secret Santa was also a huge success and a lot of fun!
Howdy Halloween
The Li Lab celebrated another Halloween with the Department of Biochemistry and Biomedical Sciences by participating in the annual costume contest. Graduate and undergraduate students united to put together a winning Cowboy Rollercoaster themed group costume. Visit the BBS Facebook Page to see all the other great costumes.
Turning up the Volume on Target Detection
Check out the Li Lab’s latest publication in Angewandte Chemie International Edition, “Biosensing by Tandem Reactions of Structure Switching, Nucleolytic Digestion, and DNA Amplification of a DNA Assembly”. Postdoc Meng Liu has developed a novel, high sensitivity DNA based signal amplification technique using an isothermal DNA polymerase and structure switching DNA aptamers. This work brings DNA aptamer based detection technologies another step closer to convenient and cost effective point of care applications.
-Jim
Hot off the Bench
Evolution of an Enzyme from a Noncatalytic Nucleic Acid Sequence
Life as we know it requires thousands of biological molecules, called enzymes, which carry out chemical reactions and allow life to exist. These molecules did not appear out of thin air – they evolved out of a mixture of the Earth’s first compounds, known as prebiotic soup. One theory for how life originated is known as the “RNA World” Hypothesis: ribonucleic acid (RNA), capable of both encoding information and performing enzymatic reactions, could have been the initiator of the origins of life, bridging the gap between life and non-life.
In this project, we used a sequence of DNA as a proxy for RNA in the origins of life. Wesubjected it to a process called in vitro selection, where we randomly introduced small variations in the sequence and then obliged the sequences to carry out a reaction. The sequences were filtered – only sequences able to perform the specific reaction were permitted to survive. These unique sequences were then subjected to cycles of this process – induction of small variations, and segregation of competent sequences. Using this method, we were able to take a sequence which was incapable of an enzyme-like reaction, and evolve it with minimal changes into a sequence adept at executing the reaction. This experiment allows us a tiny peep into how RNA molecules could have acquired function at the brink of the origin of life.
-Rachel Gysbers