What is smaller than bacteria?

At the "Pupils' Science Day", HKI researchers answer the questions of almost 30 curious students

| by Christine Vogler

Group photo: 27 pupils visit the HKI

Impatiently they listened to the instructions - some theory is required. But finally the practical work starts: 27 pupils explored the HKI in a total of nine groups for the "Pupils' Science Day" ("Forsche Schüler Tag"). Some of them visit the institute for the second time in the course of the career orientation day, which takes place at the same time as the nationwide "Girls' and Boys' Day".

"Don't be shy," Sebastian Pflanze encourages the students in his group. "You can't do anything wrong." The doctoral researcher of the Junior Research Group Chemistry of Microbial Communication measures 15 mg riboflavin (vitamin B2) with Jette and Emilia from the Holzland Gymnasium. The students tentatively put the orange-red powder into a white plastic bowl on the fine scale. In their experiment, the eighth-graders analyse vitamin B2 from vitamin tablets.

Meanwhile it's quiet as a mouse next door. Esther and Victoria stand reverently in their large lab coats in the laboratory of the Junior Research Group Evolution of Microbial Interactions. They don't dare to touch anything. After centrifuging yeast cells, they stain the cell wall of the fungus with different dyes. "At school we have stained the nucleus of onion cells," said Victoria, who is slowly becoming a researcher. They proudly present their colored samples to the camera before diluting the solution. Doctoral researcher Christin Reimer explains to the students that the cells can be better recognised later thanks to the staining. They want to bring the yeast cells together with amoebae and observe what happens under the microscope.
"Now we have to wait 30 minutes while the samples are in the incubator at 37°C," adds biology laboratory assistant Lisa Reimer.

Meanwhile, in the lab next door:
Sebastian holds a UV lamp in front of a glass container with yellow liquid. "Do you see the bright spot where the substance fluoresces?" he asks the students. It's a little too bright in the lab, but Jette and Emilia are getting closer. They nod. "We will use this property later for quantification," explains the chemist.

The colours of Victoria and Esther also shine, but from the microscope monitor. "You see," calls Christin. "Here the yeast has already been eaten by an amoeba cell, even though we just put them together." The students look excitedly at the screen and grin with joy.
"So, what's going on?" Junior Research Group Leader Falk Hillmann enters the room. He is curious: "Wow! you recognize the cells well", he praises the temporary researchers." You did a great job. When can you start working in our lab?"

(Monika Weiß)

Impressions from the "Forsche Schüler Tag" 2018