After completion of formal education, the mass media represent people's primary source of scientific information. Besides the traditional attention to scientific knowledge, national curricula are therefore increasingly emphasizing critical and reflexive engagement with media content as a key objective of science education. Despite this curricular emphasis, there are few methods for teaching media literacy in science class. Here, we apply frame analysis to meet this challenge. Based on a previously described framing scheme for classifying gene-related information into five gene frames, we developed a pilot teaching programme for upper secondary school biology. Thirty-four students from two parallel classes were taught how to identify gene frames in media texts. The programme was placed at the end of their conventional genetics teaching, so that the students already had a basic knowledge in genetics. Learning outcomes were evaluated with pre- and post-test word association maps and focus group interviews, as well as analysis of the classroom work. We found that the students fully grasped the idea that there are different ways of framing the gene concept and they were able to recognize the different gene frames in newspaper texts. We also saw a shift in how the students used the gene concept, from a simplistic and deterministic perspective to a more dynamic and evolutionary understanding of genetic causation. In addition, the students became more critical of media claims. We, thus, conclude that frame analysis of gene-related news stories represents an effective activity for promoting media literacy and more insight into genetic causation.