Fish on chips, or how Kristin Schirmer saves animal lives

Article from the Info Day Magazine 2022

Fish on chips – what sounds like the national dish of the British is actually the result of an extraordinary career as a researcher that was originally planned quite differently.

Kristin Schirmer, born in 1967, grew up in Dresden in the former GDR. In her free time, she spent a lot of time in the nature, especially at a small pond near her parent’s flat. “It wasn’t anything special for me; I’ve always liked being in the nature and doing biology, chasing tadpoles and catching water fleas.” However, there was a second passion alongside this: sport. And since teachers were in demand in the GDR at the time, it made sense to Schirmer to start training as a sports and biology teacher after school, especially since she passed the demanding entrance examination for this course.

It was a sports accident that ended her career as a teacher. But instead of being discouraged by this, she switched to studying biology and pursued this path with the same commitment as she had previously demonstrated for teacher training. After the personal change came the political one in 1989: “Despite a happy childhood, we felt constricted, so it was fortunate that we were able to experience the fall of the Wall.” Schirmer thus seized the first opportunity she had to move to West Germany. Together with her husband, whom she had already met at grammar school, she moved to Stuttgart in 1991, where she was able to continue her education at university.

Canada as a signpost

But it didn’t take long for them to move on: Canada was their next shared dream. With her characteristic determination, Schirmer managed to get a place in Waterloo (Ontario) at the same university where her husband wanted to do his doctorate – in the laboratory of Niels C. Bols, a renowned cell biologist. It was Bols who taught her how to isolate cells from rainbow trout and grow them on a nutrient medium to produce a cell culture that could be multiplied indefinitely. When Bolls offered her a PhD position in his lab, it soon became clear what objective she would pursue in the future: to use the fish cell lines to replace animal experiments, even though “at the time, nobody could believe this would work at all,” says Schirmer.

Before a chemical is put on the market, it must be ensured that it is safe for humans and the environment, for example that it does not harm organisms living in the water. One of the most common tests carried out is the acute toxicity to fish. This involves exposing fish to increasing concentrations of chemicals in aquaria and observing how quickly they die. Millions of fish die in this way every year – a state of affairs that is not only untenable for Schirmer.

Credit to many people

What began more as a coincidence therefore became a passion for Schirmer. Also as a postdoc (in Canada and Leipzig), as Head of the Cell Toxicology Department (Leipzig) and since 2008 as Head of the Environmental Toxicology Department at Eawag, she did everything she could to develop a toxicity test that uses their cell lines instead of the fish themselves. In 2016, Schirmer founded “aQuaTox-Solutions” together with other experts. An Eawag spin-off that offered the cell line test method commercially for the first time, attracting widespread interest from industry. Schirmer and her team achieved the big breakthrough in 2019 when the International Organisation for Standardisation approved the test as an “ISO Standard”. Two years later came the ultimate crowning achievement; the OECD gave the green light for the fish cell line test. This means that companies and authorities around the world can now determine the environmental toxicity of chemicals without having to resort to animal testing “We are extremely happy that we have managed to do this and that Eawag has always supported us,” says Schirmer. “The fact that we have been so successful in recent years is thanks to many people. We have managed to keep working in this area despite intermittent resistance, and it’s paying off now.”

Cells of a rainbow trout gill cell line (RTgill-W1) enlarged (blue: stained cell nucleus, red: cytoplasm)
(Picture: Sven Mosimann und Barbara Jozef, Eawag)

Still many objectives ahead

It is this perseverance, coupled with courage and flexibility, as well as trust in a large network that have brought Schirmer to where she is now. But also the certainty of fighting for a good cause. In general, it is important to her to think about daily actions and how we can live more sustainably. That is why, for example, she has chosen to be a vegetarian. “For me, it all hangs together and therefore it’s also a lifestyle.” She also conveys this global view of things to her students in her teaching – as well as to her own two children, who are now themselves studying. That she has not lost her original passion for teaching is shown by the prize that the EPFL students awarded her in 2021 for her commitment as a professor.

But she is not one to rest on her laurels. She still has many objectives that she would like to achieve professionally. It is particularly important for her not to lose sight of the practical side of things: “I have learned over the past few years that we as scientists often have the feeling that the data speaks for itself and that everything is logical. But it doesn’t work like that. We should involve stakeholders from the beginning and think about which key points are important to them and what we can achieve together.

Chip with six channels (left) into which the cells are seeded. Small circles on the chip represent the electrodes that measure the resistance of the cells.
(Pictures: Jenny Maner, Eawag)

Fish on chips is now also at the top of the agenda. In the laboratory, an Eawag team of researchers and technicians has already succeeded in growing fish cells on microchips equipped with electrodes. This allows the resistance of the cells to be measured, which in turn indicates how well the cells are doing. Next, the researchers want to bring these biosensors into the field to study directly how toxic the water is in the river or lake. The first tests have already taken place on the LéXPLORE platform on Lake Geneva (see article p. 14) “So far, however, there are still many problems, and we are only in the development stage. We’re working on the idea that soon we’ll be able to track live toxic load on the cells using a smartphone, without endangering a single fish life.” Anyone who knows Kristin Schirmer has no doubt that she will also achieve this objective.

Created by Christine Huovinen for the Info Day Magazine 2022