Our out-of-school practical exercise was designed to bring upper secondary school students in contact with one of the most exciting and expanding topics in biology today: epigenetics. In school, students only study the basics in genetics and the respective investigation techniques as provided by the syllabus. For a practical exercise in epigenetics, however, they need additional knowledge. Hence, they are introduced to the subject of epigenetics and its molecular mechanisms. Students are asked to examine the different DNA methylation conditions of lambda DNA using both a restriction assay and gel electrophoresis in an out-of-school laboratory. DNA methylation is one of the major epigenetic mechanisms which have significant effects on gene expression; studies on monozygotic twins have shown that it is influenced by the environment. This exercise enables students to correctly identify the different methylation conditions of distributed lambda DNA samples. In doing so, they receive a first introduction to one epigenetic mechanism. The necessity for students to experience science in out-of-school settings has been shown by several scholars. The practical exercise we are proposing in this article was elaborated for such learning opportunities for upper secondary students to gain insight into contemporary science issues.