Need a low-cost, rapid, point-of-use method to detect water contaminants? Check out our paper 'Cell-free biosensors for rapid detection of water contaminants' in @NatureBiotech from @NorthwesternU led by @kirstenjung93 and @biochemPhD: https://www.nature.com/articles/s41587-020-0571-7 (1/10)

In honor of Rosalind Franklin, we call our method ROSALIND for RNA Output Sensors Activated by Ligand INDuction. It uses allosteric transcription factors and fluorescent RNA aptamers to create visible signals when contaminants are present. (2/10)

Programming the transcription factor operator sequence to be between a T7 promoter and a broccoli sequence creates a regulated transcription reaction that responds to a chemical target. By using only RNA we can generate signals faster than by using GFP! (3/10)

What's cool is that ROSALIND is modular - detect a different chemical by changing the transcription factor/operator. Here's a panel of 16 different chemicals important for water quality including antibiotics, personal care compounds and metals such as lead and copper. (4/10)

Is ROSALIND specific? Yes! We implemented a very cool RNA logic gate (a NIMPLY) to fix cross-talk issues! Thanks to @FrancoLabUCLA, we could use their RNA 'kleptamer' to cancel out crosstalk signal - no protein engineering required! (5/10)

Is ROSALIND sensitive? Yes! Here's another awesome RNA feedback circuit to improve sensitivity for antibiotics. Thanks to @suess_lab, we could use their anti-TetR aptamer in a feedback loop to shift the TetR dose response curve. (6/10)

Does ROSALIND work in the field? Yes! Led by @SandrineMatias1, we packaged and shipped reactions and tested them in Paradise, CA. We found high levels of metals due to the 2018 Camp Fire that we could detect with ROSALIND. (7/10)

This work was made possible by an amazing team effort including @MVerosloff @phillip_clauer @SandrineMatias1 @capdevilalab @giedroclab @MDesmau (8/10)

And please follow the great women scientists that made this happen @WomenScienceRFS including @kirstenjung93 @SandrineMatias1 @capdevilalab @MDesmau ! (9/10)

And the incredible environment at @NUSynBio @NUWaterCenter @NorthwesternU @NorthwesternENG @ResearchNU @broadinstitute @wyssinstitute @cedeuschile @ingenieriauc with grateful support from @NSF (10/10)