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.
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.
Last Sunday March 29th, five members of the Li Lab ran Hamilton’s Around the Bay Road Race, the oldest race in North America. Kha, Shahrzad and Zohaib ran in the 5 km race, while Dingran and Rachel joined Fazmin from the CMCB in running the 30 km race. The event was exciting and these members of the lab were thrilled to finish and receive medals celebrating their accomplishments. They’re looking forward to surpassing their times in next year’s race!
This year, the Li lab was proud to have three graduate students represent them at McMaster’s 3-minute thesis competition. On February 11th, Sepehr, Dingran and Rachel all presented their research to a non-specialist audience in less than three minutes. These three students made up three quarters of those representing the Biochemistry & Biomedical Sciences Department. Although none of them made it to the finals, they found it an interesting and engaging experience.
The holiday season was busy time for the lab. As snow piled up outside, the Li lab decided to spice up the winter with the perfect combination of mystery and excitement – a Secret Santa party! Although Dr.Li offered to give the best gift of all time (designing a figure for any upcoming journal publication) unfortunately he was not able to attend the party due to a conference in Singapore. As the Li lab spends a lot of time with each other in the lab on daily basis, we saw each others’ inner playfulness reflected in our gifts. Kha received a colour-changing mug from Jim in which showed a molecular beacon figure when containing hot water.Some of us received mini Lego sets, stuffed animals and even a kitten book for bed time. Most of people did a great job disguising themselves and really made it challenging to guess the identity of their secret Santas. The party ended in everyone’s laughter and a group photo. We thank Dora and Qian for their enthusiasm to organize and host the event and we hope all our readers enjoyed a great holiday and a Christmas full of laughter!
I represented the Li Lab at Spectrum’s Pitch Competition this past Monday evening. After presenting our innovative colour-based assay for heavy metals, I was selected as one of the 12 finalists out of 40 groups that presented. The finals is this Monday November 24th, at 6 to 8pm at TwelvEighty in McMaster University. There are prizes for up-to 2500 dollars for the winners of the competition. Everyone is encouraged to attend. Myself and everyone at the Li Lab hope to see you there.
Members of the Urease Group from the Li Lab attended this year’s Innovation Showcase this past Wednesday. In addition to a keynote address, technology presentations, and round-table discussions, there was a poster presentation competition in which the Li lab displayed two posters.
Throughout the day, the audience showed tremendous enthusiasm towards our projects, and provided some valued feedback that will guide our future directions. The audience’s fascination in our projects eventually attracted the reporters at the event, leading to both Sepehr and Qian being interviewed by multiple news networks about their respective projects, including CHCH news and Ignite news.
Sepehr’s poster presentation, put together with the help of Dingran, Kha, and Qian, was selected as one of the finalists out of the 50 presenters at the event.
In the finals, Sepehr presented a captivating 2-minute pitch, describing the kit we’ve developed for the color-based detection of heavy metal toxins. After judges convened, we were selected as the runner-up for the commercialization-ready category.
Following success at this event, we will be presenting at similar competitions in the near future. Come see our next presentation at the Spectrum Standup Pitch Competition November 24th.
It is a Li lab tradition to attend the Halloween costume and pumpkin carving competition hosted by the Department of Biochemistry and Biomedical Sciences at McMaster University every year. This year, Rachel organized a movie night for The LEGO Movie, which inspired the Li lab to dress as Lego characters for the event. In order to create winning outfits, everyone from the Li lab was eager to show off their artistic side and really demonstrated just how many ways in which cardboard boxes, Bristol board, tin foil and paint could be manipulated. In the end, 12 characters from the movie were made, and the Li lab took home 1st place for best costume and 2nd place for best pumpkin. It was awesome!
– Dora H
Last week, our publication entitled “Translating Bacterial Detection by DNAzymes into a Litmus Test” was published in Angewante Chemie. The article was well received and was featured on several social media outlets. We were also excited to be featured on the back cover of the journal in which our very own Qian Feng conceptualized the artwork. Since then, we have put together a fantastic team to move this technology forward and to open up new avenues of research. It has been a very satisfying process to see two years of our hard work receive so much attention and we are excited to see how this technology will continue to grow!
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