In this study, we describe a method to employ a conventional compound light microscope, usually available in laboratories, to obtain fluorescence. In particular, two pieces of colored acrylic plastic were utilized to assist the microscope in filter performance. We also attempted to examine the applicability of the setup by staining onion cells with highlighter ink. This activity is intended to serve as an experiment for life sciences courses using physics-based methods in a biological context. This setup has the advantages of ease of use and low cost.