IN THE CLASSROOM change the magnification and make their own measurements, whereas the instructor Looking at education or the lab manager carries out more sensitive operations such as debugging instrument errors. Two students take turns sitting beside through the microscope the instructor during the demonstration. Given these logistics, the class enrolment is Suhas Eswarappa Prameela , Patricia M. McGuiggan, capped at between 10 and 12 students to ensure Amy Brusini, Trevor W. Glenn and Timothy P. Weihs their learning experience is maximized. In the advanced light microscopy lab, Advanced research microscopes in universities can be used to enhance the students look at blades of grass, fine grooves education of STEM students, as demonstrated by initiatives at Johns Hopkins on keys or coins, human skin cells and mouse University that give students the opportunity to get hands-on experience with cells. Using a scanning electron microscope, sophisticated microscopes. students explore the microscale features of spiders, porous structures in butterfly Like many disciplines, STEM education at the teaching and training of students through wings and layers of paint from a wall. Using university level has undergone tremendous specialized classes, university-sponsored a TEM (Fig. 1a), students observe viruses, change in the past few decades. Today’s STEM grants, government-sponsored internships nanocrystals and atoms in metallic materials. students have increased access to a range of and apprenticeships, and other externally The colourful contrasts from fluorescence specialized courses, research experiences for funded projects. Here, we highlight the and polarized light microscopy and the high undergraduates and competitions centred lessons learned from these initiatives in the level of magnification that can be achieved by on science projects and inventions. In the hope that faculty and administrators at other electron microscopes are often intriguing for classroom, STEM instructors are moving universities can create a similar infrastructure the students. Active learning exercises help away from traditional lecture-based teaching to support grants, classes and programs students acquire core concepts behind the and are incorporating more active learning aimed at expanding education in the field techniques more effectively than standard strategies, such as inquiry-based, collaborative of microscopy. classroom instruction. For example, hands-on and case-based learning. Complementing this activities, such as building crystal structures student-centred approach, STEM departments Integration of microscopy tools using ball- and- stick models or virtual software are organizing lab tours, giving undergraduate At JHU, we offer several integrated laboratory tools, allow students to engage with the research assistant positions and allowing access and lecture courses, including short, one-credit information in multiple ways. to research equipment typically reserved for (equivalent to ~40 hours per semester) classes In these classes, groups of two to three graduate students, postdocs and research to undergraduate students taught by PhD students also deepen their understanding of a professors. For example, microscopes can students and post-doctoral scholars through microscopy technique by choosing a research play a critical role in opening up scientifically programs such as Hopkins Engineering paper from a preselected list and presenting compelling topics to students, as well as giving Applications & Research Tutorials (HEART) the main findings to the rest of the class. The them valuable skills and hands-on experience. and Special Opportunities for Undergraduate students’ presentation topics range from Undergraduate students typically have Learning (SOUL). These classes expose studies of lithiation of silicon in batteries using access to simple light microscopes in their students to cutting-edge research work operando TEM to imaging skin cells using practical sessions; these microscopes are on campus and draw students from many fluorescence microscopy. Such focused logistically easy and low cost and can be used scientific disciplines, as well as from the social activities help students appreciate the real-life by many students at once. More sophisticated sciences and humanities. Classes range from applications of microscopes, as well as how research microscopes, such as confocal or gene therapy to machine learning. research keeps pushing the capabilities of fluorescence light microscopes and scanning Among such courses, Looking at atoms imaging methods. or transmission electron microscopes (TEMs), and viruses is a microscopy characterization One of the main lessons we have learned are more difficult to make available to class that focuses on teaching fundamentals from the HEART and SOUL classes concerns undergraduates. However, there is much to be of both light and electron microscopy. Every the selection of samples to study. In the first gained from leveraging these tools to enhance other class is spent in a laboratory probing iteration of these classes, we used only metallic the education of undergraduate students, different materials. Because students are not samples, but many students in the biological as they enable them to gain a competitive officially trained on the microscopes, they sciences expressed interest in learning edge to obtain internships, jobs and research cannot independently operate the machines. how microscopy could be applied to other assistant positions in labs, and to enter graduate However, students have the opportunity materials. Since then, we have expanded the programs. At Johns Hopkins University (JHU), to handle samples and to make their own. choice of samples by taking suggestions and several researchers and STEM educators Once a sample is ready, and the scope is tuned feedback from the students. are involved in programs to integrate to the correct settings, students operate the At the School of Medicine, postgraduate advanced characterization methods into the position controls to navigate the sample space, students are offered characterization-oriented NATURE REVIEWS | MATERIALS VOLUME 5 | DECEMBER 2020 | 865 IN THE CLASSROOM a b c 200 nm 500 nm 1 μm Fig. 1 | Teaching with microscopes. a | A transmission electron microscope (TEM) b | A TEM micrograph of bacteriophages from the Phage Hunters Project. c | A TEM image of nanocrystals in a magnesium alloy for the Materials in Extreme Dynamic Environments (MEDE) programme. Panel b courtesy of M. McCaffery and the Integrated Imaging Center, Johns Hopkins University. classes similar to HEART and SOUL but broken or replaced parts of the filament or Microscopy Australia, in partnership focused on techniques used in medicine apertures that go inside the microscope. with several universities, has developed and the biological sciences. Students learn By co-teaching small classes, they can provide an excellent open-source platform called how confocal, fluorescence and electron support in designing activities and give Myscope Microscopy training. Through this microscopy techniques are used to study exposure to the instruments and to their website, anyone can access a wide variety of cells, evaluate disease processes and aid research activities in the short class periods. microscopy-related educational materials in diagnostic decision making. In virtual These undergraduate microscopy initiatives and operate virtual microscopes. microscopy classes, students examine images have already started showing results at JHU. When developing and implementing using an online database, which allows them Of the students who took these classes, a few specialized classes such as HEART or SOUL, to see a wide range of images of pathological have joined research groups where they plan soliciting feedback and making improvements processes and contributes to a better to use the microscopes and to gain more is crucial to designing more effective class understanding of how microscopy is used training. The students remarked that the materials and syllabi. The addition of in medicine. HEART or SOUL classes prepared them to the simulation tutorials developed via the The use of microscopy in medicine is also apply to study in the research laboratories of technology fellowship grants is one example. taught at the undergraduate level. JHU, in professors on campus. In addition, some senior Initially, student evaluations averaged 3.8/5 for partnership with Howard Hughes Medical undergraduate students have started using both the overall quality of the course and the Institute as part of the Science Education microscopes extensively before transitioning effectiveness of instructor teaching. Once Alliance, launched the Phage Hunters to Master’s or PhD programs. A few of them simulation tutorials, more lab visits and active Project (SEA-PHAGES program) a few years mentioned that they knew they would have learning exercises were incorporated, the ago. In this program, two dozen freshman limited ability to take characterization- oriented ratings improved to 4.6/5 for overall quality students dig up samples of soil and isolate classes during the first year of their new of the course and 4.3/5 for the effectiveness of a phage, a virus that infects a bacterium, programs, thus having taken the HEART or instructor teaching. and image it using a TEM (Fig. 1b). Through SOUL classes before starting helped them Lastly, we are training several under- this opportunity, students gain hands-on to feel more prepared. graduate