Nienke van Dongen is a postdoctoral researcher at the University of Twente in the BIOS lab-on-a-chip group, working on early cancer detection in urine. She won the Spotlight Prize 2022 for her pitch on her PhD research.
What did you study?
’Molecular Biosciences in Wageningen. I considered studying chemistry, but my parents had both done it and I wanted to do something different from them. In the end, this was a suitable study if you couldn’t decide between biology, physics and chemistry. At the information day, they showed how all the Nobel Prizes overlapped with the course of study. I thought that was a great argument.’
Why do you use CRISPR-Cas for biosensors?
‘I switched from nanoparticles to CRISPR-Cas research during the Corona pandemic because I had a lot of time to think. I started writing a review on CRISPR-Cas diagnostics and then started looking at how we could use it for cancer detection. When I started, there were not that many biosensors using CRISPR-Cas. People sometimes think I am doing genetic engineering, but I am using it to detect DNA sequences. The variant we have can bind to DNA, change the structure of the protein and then cut anything in its vicinity. It is a natural amplification method. The CRISPR-Cas binds once but cuts very often, so you get a natural amplification of your signal.’
What is the most challenging part of the study?
’Detecting really very low concentrations. The DNA strands we are looking for are in atomic concentrations, below femto- or picomolar, or *10-18. I have mainly worked on the method. Now I am trying to use microfluidic chips to detect at very low concentrations. I can now measure picomolar, but I want to be able to measure one millionth of that. I do this by dividing the liquid into many small droplets, called microfluidic chambers, where the local concentration is high enough to measure.’