Meeting Abstract
73.3 Thursday, Jan. 6 Microtomy and Histology in the High School Biology Classroom WHEELER, Maxwell D*; BARBANO, Duane L; NELSON, Russel L; UYENO, Theodore A; Northern Arizona University; NAU; NAU; NAU mdw62@nau.edu
The purpose of the Open-tome project is to develop economical microtomy (thin-sectioning) and histology (micro-anatomy) for use in high school biology classes. The ability to deconstruct microscopic structures, such as a plant root caps and insect joints, and to visualize the internal organization allows an intuitive understanding of three-dimensional structures. Such techniques also form the basis for further functional, biomechanical, or physiological investigations. Histochemical (slide staining) techniques used to identify tissue components also allow discussion of zoology, botany, medical pathology, and biochemistry questions. In most high school classrooms, however, microtomy is reduced to magnified observations of hand-cut slivers of celery stalks or onion peels. This technique, while inexpensive, is dangerous and resultant jagged sections are too thick for compound microscopy. To improve this experience, we designed and school-tested the Open-tome, a durable microtome that is cost effective (using recycled materials) and is both precise and simple to build (by using bolt-on components that include machine precision sliders, stepper motors, and gear reducers). Open-tome allows students to cut serial paraffin sections as thin as 10 μm by setting a simple Arduino controlled interface which then electronically advances the sample and counts the number of sections that the student cuts. The lever actuated cutting movement keeps the student’s hand away from the cutting blade (a single-edged razor blade). Open-tome is an open source design: its design specifications and protocols are freely available via the internet in order to ensure low-cost availability, to allow for user generated improvements, and to maintain an up-to-date wiki-style series of protocols and experiments that are compatible with required teaching standards and objectives.
