More than 700 visitors got to know the Science Faculty during the Leiden Science Family Day. This is a day where family members of those working and studying at the Science Faculty of Leiden University as well as the general public are invited to visit the science faculty and learn about the intriguing science happening there. People of all ages could enjoy fascinating experiments, tours, interesting lectures, spectacular nitrogen shows, and various workshops. It was an informative day with many (future) scientists, amazement, and above all, many happy faces².

Those who visited this event were of all ages and knowledge levels. Since it was an informal family event, we developed our materials with mainly the young visitors in mind. Therefore it was a priority for us to use materials that engage the audience by being interactive.

One of our team members produced some wonderful microbial artwork on agar plates using bacteria expressing GFP and different colors. Using a UV flashlight and protective goggles, visitors were invited to inspect the difference between fluorescent plates and those without fluorescence. They were asked what the difference is between the two. This was used as a segway to talk about DNA and what information it contains. When asking these young curious minds what they know about DNA, we were amazed by how concise and accurate some of their answers were!

After the concept of DNA is made clear to everyone, visitors could immediately feel what it is like to do SynBio using our plasmid game. In this puzzle, a circle containing two rows of complementary colored squares representing base pairs is presented. A dotted line representing the recognition site of a restriction enzyme is visible and the visitor is given three different DNA inserts along with the challenge to pick the one insert that could fit the sticky ends of the double-strand break (see image below). The solution is to look at the colored squares of the overhangs and pick the insert with complementary bases. And so they have made their first insert! We explained that this insert can introduce many different kinds of traits that an organism did not possess before, as is often the case with GFP expression.
This often sparked a conversation with visitors of all ages about the many different possibilities that SynBio opens up, and they were challenged to think about what other traits might be useful to introduce into organisms. Crops that are more nutritious and resistant to pests are a common example in such discussions. Thus this plasmid game did exactly what we designed it to do, which was to engage a wide audience and get them to think about the many applications of SynBio and gain interest in the topic.

Finally, it was time to get creative. We prepared many agar plates in advance and provided our young visitors with a cotton swab. They were then invited to sample anything they could think of. And sample they did! No surface was left unstudied. The floor, table, doorknobs, each other, phone screens, and even their own tongues and nostrils were subject to careful scientific exploration. With some guidance, these scientists of the future applied their swabs to their agar plates. They learned how to properly seal and label the plates and were instructed to keep it in a warm place for a few days. This allowed them to keep track of their microbiology experiments and gain awareness of the living microorganisms around us. This quick workshop gave people hands-on experience with microbiology in a safe, fun, and engaging way.

It was a wonderful and educational day! The aftermovie can be seen by following this link.

During Musemnacht Leiden many of the city’s various museums open their doors, giving visitors the unique opportunity to experience these locations in a different light. Museums organize special activities including lectures and workshops. Rijksmuseum Boerhaave is the Netherlands’ treasure house of science and medicine and the winner of the European Museum of the Year Award 2019, and we were fortunate enough to be an important part of their program.

The Museum Night attracts an audience eager to learn and discover more, so we developed materials fitting that need. Keeping with Boerhaave’s theme of science history, we showcased the history of biotechnology. It was still a priority for us to keep things interactive and engaging. One way we did this was by distributing our materials over three sections: Traditional Biotechnology, Modern Biotechnology, and a Microscope Slide Workshop. These three sections will be discussed further below.

Modern Biotechnology

For the modern side of biotechnology, we created and displayed a poster showcasing some examples of what SynBio is used for in the modern era. The poster, shown below, contains a minimal amount of text. This encouraged curious visitors to engage in conversation with us about how these applications came to be. It was frequently met with amazement when people learned that ‘golden rice’ was made by inserting two genes from daffodils and one from a bacterium into the rice genome, hereby creating a rice strain capable of producing a precursor to Vitamin A - and that this was done to alleviate the onset of blindness linked to Vitamin A deficiency in children across South Asia³. This and other varied examples of useful SynBio applications brought up the question of how this kind of transgenic organisms are created. Our previously developed plasmid game was once again the ideal tool for communicating in an interactive manner how one might introduce a novel trait into an organism's genome. In addition to these two elements, we had a microscope set up with various pre-made slides, such as one of marine diatoms, to highlight some extremely common but little-known organisms.

Microscope slide workshop

We offered visitors the opportunity to prepare their own microscope slide and view them through a microscope that we had attached to a monitor so others could also see what was going on. Various things could be viewed such as yeast cells from our live culture, allowing us to explain the budding way of asexual production. Visitors could also take a swab of their own Buccal Mucosa cells and spot a nucleus containing their own DNA. Furthermore, they prepared slides from the SCOBY or a water sample taken from a local pond. Finally, some even brought their own sample to view them from under the microscope! One lady enthusiastically presented a piece of moss hoping to spot a tardigrade.

The Midsummer Night Festival is a cultural event organized every year by the Hortus Botanicus Leiden on the evening of the summer solstice. A broad range of different types of people attended from students to family members to tourists and curious locals. There was music, food, entertainment, and the iGEM Leiden 2022 team! Due to this event taking place in a garden, we decided to tell the public about how crops are bred and favorable phenotypes are obtained using various techniques. We focussed on three techniques: classical selective breeding related to mendelian genetics, random UV-induced mutagenesis and selection, and finally modern accurate genetic tools like CRISPR. This comparison was done to get people thinking about what GMOs actually are, how they relate to GM methods, and the current state of GMO regulation. We also provided people the opportunity to combine genetic elements representing certain traits to create their own ‘organism’, much like a synthetic biologist would do. Since this was an event where people can freely walk by, we again sought to be as interactive and engaging as possible. How this was done for each part is discussed below.

First up is classical selective breeding; Choosing which individual plants to breed with one another to raise the chance of obtaining progeny with certain characteristics. Wild carrots, which are very small and white, could be seen next to their modern orange counterpart. This showed the huge changes brought about using only selective breeding. The same was done with wild and cultivated African Violets, with the modern variants having bigger and differently colored petals.

Next, was the method commonly used for food crop improvement in the EU: random mutagenesis and selection for improved phenotypes, mainly using UV radiation to introduce mutations in the crop genome. Visitors could play a beer pong style game, where each cup represented a mutation with an effect unknown beforehand. Only after they successfully threw the ball in a cup could they find out what mutation they introduced. At times this was a good change such as a more nutritious apple or one resistant to pests, other times the induced change was negative or even had an unknown effect. We used this game to convey the random element of this way of crop improvement. In a sense, it is a shot in the dark and inaccurate, much like the ping pong throwing game. Only after throwing many balls and hitting off targets with negative or unknown effects is it likely that a positive change is introduced, even if you know which gene you want to hit. Would they eat this apple with a multitude of changes in its genomes with an unknown effect? Many were uncertain.

Finally, we came to a portrayal of modern and accurate genetic modification techniques. Their relative accuracy and ease of use were demonstrated by having visitors throw a volleyball at a stack of cups at point blank range. Piece of cake! Much to the enjoyment of many visitors who had just struggled with the more challenging pong style game. We explained that with techniques like CRISPR, changes can be introduced in plant genomes that are targeted, specific, and accurate. However, these techniques are currently not allowed to be used in the EU when the crop is destined for human consumption. Instead, crops undergo the chance-based process of UV-induced random mutagenesis as explained previously. This raised some eyebrows, especially when told that CRISPR is approved for use under strict conditions elsewhere in the world. Using these games we successfully got people thinking about what GMOs are, how they’re made, and what a ban on GM techniques actually means in the place they live.

To get people creative, we developed a way for people to think like true synthetic biologists. By combining three phenotypical elements such as petal color, shape, and special features, visitors could create their own flower from a huge number of possible combinations. This was especially useful in conveying the idea of biobricks to the young visitors at the Midsummer Night Festival!

In 2022, Leiden is Europe’s City of Science! This means many events and activities surrounding science are organized throughout the year. In order to engage members of the public who are not immediately interested in science, we joined the Leiden Beer Festival in collaboration with the City of Science team in Leiden. Here we asked beer lovers if they knew about the organisms essential to the production of their beverage and gave them a chance to view them up close through a microscope. We discussed how and why it is that yeast converts sugars to carbon dioxide and ethanol, and demonstrated this with a balloon covering a bottle of yeast fermentation broth which inflated with CO₂ over time. Learning from the past, we updated our microbe match game to include a more varied set of foods and organisms, and once again it proved to be a fun and engaging game that made people aware of the role of microorganisms in their food and drinks. Using the posters and plasmid game that we developed we were able to engage this audience that was not primed at all to learn about SynBio and get them excited about all its possibilities. Cheers!