Team:TU Munich/Human Practice/School Visit

Article written by a pupil of the school magazine

On July 24th, 2012, two students of the iGEM (international Genetically Engineered Machine competition)-Team of the TU Munich visited us. We attended an interesting presentation about this competition which takes place in Boston since 2003 and they explained us that their research goal is to manipulate the DNA in such a way that the cells get other characteristics. The project of the team is to manipulate yeast (Saccharomyces cerevisiae) to produce useful ingredients naturally on his own. As we all know, yeast is normally used for baking and brewing beer. Their goal is to transform normal yeast into "superyeast". Therefore, herbal enzymes in the form of external DNA will be inserted in the yeast. But buying a beer brewed with "superyeast" in a supermarket is very unlikely. Anyway we produced with the students of the TUM our own chemical beer, which one should not drink.

They also explained us that iGEM does not only include the work in the laboratory but also the so called “Human Practice”. “Human Practice” means anything that is done in the context of the project outside the lab. Finally their visit was part of their "Human Practice" program.

The first experiment they made with us was DNA-extraction from plants. This meant that we squished a banana to destroy the cells. Then we mixed it with salt and dish liquid to destroy the membrane of the cell, and added isopropyl alcohol at the end. After a while we could see the DNA. Afterwards we did another experiment: a gel electrophoresis. That is a common method to detect DNA. We poured the gel for the electrophoresis. This cannot be done in school in this way because we do not have the right equipment for it. For the gel electrophoresis we used a completed gel, that was made by another class.

Fig. 1: Logo from the school magazine

We were not only informed about DNA but also about enzymes. Therefore, we squished again some fruits (this time pineapple and kiwi). We put pineapple, kiwi and pineapple juice into bowls and added gummy bears. The enzymes in the pineapple juice can decompose the gelatin of gummy bears. Unfortunately we could not see the result because it should rest 24 hours and, of course, we forgot to look again.

Anyway the day was very interesting for us and we learned a lot about iGEM, the DNA and the way enzymes work.

Text by Corinna (16 years, student)

The school we visited

Fig. 2: Picture from the school

We visited the Joseph-Bernahrt-Gymnasium in Türkheim. About 900 pupils go to this school, located in the beautiful region "Allgäu" in Bavaria. We visited a 10th grade biology and an 11th grade chemistry class, each for the duration of two hours. [http://www.gymnasium-tuerkheim.de/ This] is the link to the homepage of the school and [http://www.spickzettel-jbg.de this] to the school magazine.

Why we came

Of course children are our future. This sentence is used a lot of times these days, but it is not the only reason why we drove almost 100 km to a school at 7 o'clock in the morning. One member of our team did her university-entrance diploma at this school. When we wrote to the school and asked for a visit the response of the teachers was amazing. Although we came at the very end of the school year, two teachers invited us to their courses. Moreover the pupils were excited about the experiments we made with them and they had a lot of questions. Explaining our project to pupils was a nice experience for us and for them. They were really interested in the broad spectrum of possibilities in science that is available nowadays and asked us many questions about our university and our fields of study.

What we did

We made four different experiments with the pupils. First we brewed a chemical "beer", then we extracted DNA from fruits. Another experiment was to test the activity of enzymes in fruits. Therefore, we "destroyed" a gummy bear with pineapple juice and last but not least we did a gel electrophoresis. Here you can see our short presentation we prepared for the pupils.

Chemical Brewing

It is based on several redox reactions, which in the end produce "yellow-brown" Iodine. Here you can see a [http://www.youtube.com/watch?v=Gp0ayLGJNe4 video] of this experiment produced by another school.

Fig. 3:Pupil with our results

DNA extraction from fruits

We extracted DNA from bananas. First the fruit was smashed, then dish liquid and salt were added. Last but not least we put the "mush" in a glass that was already filled with isopropyl alcohol. After 20 min we could see the DNA as white striation.

Enzymes in fruits

We used pineapple, apple and kiwi juice. Pineapple juice contains bromelain, which degrades gelatine in a gummy bear and, therefore, dissolves it within 12 hours. To demonstrate a negative effect, we also used Coca Cola that cannot dissolve a gummy bear.

Gel Electrophoresis

The last experiment we did was a gel electrophoresis. First we poured an agarose gel, then we pipetted the samples and a marker in the slots and turned on the electricity. After about one hour we could see the results. While waiting, we discussed the use of this method in forensics and biology.

Finally, we wanted to show the students the application of gel electrophoresis in criminalistics. Therefore, we showed them a simplified gel picture with the DNA patterns of three suspects and the DNA pattern of the DNA sample collected at a "site of crime". The pupils directly spotted the guilty suspect and explained correctly why it is possible to identify the correct suspect based on the gel photo.

Declaration of consent

In Germany it is not so easy to publish pictures of children in school. Therefore, we wrote a letter to the parents. By signing this declaration they gave us permission to use pictures showing their children during the experiments. The school supported us,too.