Technological Pedagogical Content Knowledge (TPCK) represents the teachers' professional knowledge needed to integrate technology in education. Following a design-based approach this study describes the strategies for designing and assessing an in-service science teacher education course. Data was obtained through interviews, questionnaires, using participant observation and analysis of in-service science teachers' professional portfolios. A detailed description of the research methodology and findings is given, including an overview of the implications of the study. Results show that integrating technology with a Research Teaching Perspective (RTP) could be a way to develop innovative science lessons for students. Suggestions for the creation of a design framework for the development of initial and in-service science teachers' TPCK are put forward.