September 20, 2024

New DNA Computer Assesses Water Quality: Genetic Networks Mimic Electronic Circuits

Lucks is a professor of chemical and biological engineering at Nothwestern Engineering and a member of the Center for Synthetic Biology. The papers co-authors include Jaeyoung Jung, Chloé Archuleta, and Khalid Alam– all from Northwestern.
Evaluating water from an area affected by wildfires in California. Credit: Northwestern University
Meet ROSALIND
The new system builds off work that Lucks and his team published in Nature Biotechnology in July 2020. In that work, the group introduced ROSALIND (named after famed chemist Rosalind Franklin and short for “RNA output sensors triggered by ligand induction”), which could notice 17 different impurities in a single drop of water. When the test detected an impurity surpassing the US Environmental Protection Agencys standards, it either glowed green or not to offer a simple, easy-to-read favorable or negative outcome.
To establish ROSALIND, Lucks and his group used cell-free synthetic biology. With artificial biology, scientists take molecular machinery– including DNA, RNA, and proteins– out of cells, and after that reprogram that equipment to perform new jobs. At the time, Lucks compared ROSALINDs inner workings to “molecular palate.”

” We discovered out how bacteria naturally taste things in their water,” he said. “They do so with little molecular-level taste. Cell-free synthetic biology allows us to take those little molecular palate out and put them into a test tube. We can thenre- wire them to produce a visual signal. It glows to let the user rapidly and easily see if theres an impurity in the water.”
Molecular mental capacity
Now, in the new variation– dubbed ROSALIND 2.0– Lucks and his team have actually added a “molecular brain.”
” The preliminary platform was a bio-sensor, which acted like a taste,” Lucks said. “Now we have actually included a genetic network that works like a brain. The bio-sensor spots contamination, but then the output of the bio-sensor feeds into the genetic network, or circuit, which works like a brain to perform reasoning.”
There are many cases where water quality requires to be determined consistently. Its not a one-time thing because contamination levels can alter with time.– Julius Lucks, Professor of Chemical and Biological Engineering
Scientist freeze-dried the reprogrammed “molecular brains” to end up being shelf-stable and put them into test tubes. Adding a drop of water to each tube sets off a network of reactions and interactions, ultimately triggering the freeze-dried pellet to radiance in the existence of an impurity.
To evaluate the brand-new system, Lucks and his team demonstrated that it might successfully spot concentration levels of zinc, an antibiotic, and an industrial metabolite. Giving the level of contamination– rather than an easy favorable or unfavorable outcome– is important for informing mitigation methods, Lucks said.
” After we introduced ROSALIND, individuals stated they wanted a platform that could also offer concentration quantities,” he said. “Different pollutants at different levels require different techniques. If you have a low level of lead in your water, for example, then you might be able to tolerate it by flushing your water lines ahead of using them. If you have high levels, then you need to stop drinking your water immediately and change your water line.”
Empowering individuals
Eventually, Lucks and his team wish to empower people to evaluate their own water regularly. With economical, hand-held devices like ROSALIND, that may quickly end up being a reality.
Its similar with water. There are numerous cases where water quality requires to be determined routinely. Its not a one-time thing since contamination levels can alter over time.”
Referral: “Programming Cell-free Biosensors with DNA Strand Displacement Circuits” by Jaeyoung K. Jung, Chloé M. Archuleta, Khalid K. Alam and Julius B. Lucks, 17 February 2022, Nature Chemical Biology.DOI: 10.1038/ s41589-021-00962-9.
The research study was supported by the US Department of Defense, the National Science Foundation, the Crown Family Center for Jewish and Israel Studies, and the Searle Funds at The Chicago Community Trust.

Test tubes holding water samples glow green inside an illuminator, indicating contamination. Credit: Northwestern University
Hereditary networks imitate electronic circuits to perform a variety of reasoning functions.
If just one tube glows, then the water sample has a trace level of contamination. If all eight tubes glow, then the water is significantly infected.
” We programmed each tube to have a various limit for contaminations,” said the McCormick School of Engineerings Julius B. Lucks, who led the research. “The tube with the most affordable limit will illuminate all the time. If all televisions light up, then there is a big issue. Structure circuits and programmable DNA computing opens lots of possibilities for other kinds of smart diagnostics.”

If only one tube radiances, then the water sample has a trace level of contamination. If all 8 tubes radiance, then the water is badly polluted. It glows to let the user quickly and easily see if theres a pollutant in the water.”
If you have a low level of lead in your water, for example, then you may be able to tolerate it by flushing your water lines ahead of using them. If you have high levels, then you require to stop consuming your water immediately and change your water line.”