This adaptable graduate laboratory course on protein purification offers students the opportunity to explore a wide range of techniques while allowing the instructor the freedom to incorporate their own personal research interests. The course design involves two sequential purification schemes performed in a single semester. The first part comprises the expression and purification of a recombinant GFP-binding protein from E. coli. The student-purified GFP-binding protein is then used in the second part of the course to immunoprecipitate GFP-tagged proteins, and their potential interacting partners, from cell or tissue extracts. As an example, we describe the immunoprecipitation of GFP-tagged proteins from "Drosophila melanogaster" larval extracts that are homologous to proteins implicated in human diseases, followed by western blotting to examine student experimental outcomes. However, the widespread availability of GFP-fusion proteins in diverse organisms enables researchers to tailor the second part of the course to their specific research programs while maintaining the flexibility to engage students in active learning. Student evaluations indicate a genuine excitement for research and in depth knowledge of both the techniques performed and the theory behind them.