Assessing the Effectiveness of a Novel Microscopy Technique in Middle & High School Science Classrooms

Abstract

Although research and new technologies have introduced different ways of observing microorganisms, including scanning and electron microscopy, these methods are expensive and require equipment that is typically not found in a middle school classroom. The transmission-through-dye technique (TTD; Gregg et al., 2010), a new optical microscopy method that can be used with current basic light microscopes, relies on the fairly simple mechanism of filtered light passing through a dyed medium to produce an image that reflects cell thickness. With this technique, living microorganisms look bright red against a dark background, and movement can be seen easily among dead microorganisms and debris that show up black. Since the technique is low-cost and easy to implement, it addresses the needs of practitioners and is appropriate for a wide array of school contexts. We describe a three-week, hands-on, inquiry-based unit on TTD microscopy for middle and high school students.