The Open University (OU) is a distance learning university that offering several STEM subjects as part of its curriculum. Within those courses, various aspects of physiology are taught through explanation and interactive content via the OU’s virtual learning environment. This includes presenting numerous techniques as interactive screen experiments (ISEs) to around 400-500 students per course, allowing our students to gain experience of these techniques and explore the underlying theoretical concepts. The ISEs are primed with images and data that enable students to collect individualised data and generate independent reports and interpretations. Here, we present examples how we teach microscopy online at the OU.

In both Biology and Health Sciences modules, we use three digital microscopes: a digital light microscope for presenting micrographs after histological staining, a digital fluorescence microscope for immunofluorescence staining micrographs, and a digital transmission electron microscope to showcase ultrastructure images. These microscopes aid student learning by featuring a unified interface. Storing images within a database allows easy interchange of images, facilitating the use of the digital microscopes across different levels or subject areas.

The digital light microscope serves, for example, to teach cancer biology concepts by counting Ki67-positive cells and grading prostate cancers in patient-derived tissue samples. These examples highlight the impact of cancer on cell and tissue physiology and enhance the students’ ability to visualise and understand core concepts around tissue structure-function relationships and gain an understanding in diagnostics. Similarly, the digital fluorescence microscope provides insights into the structure of organelles and alterations induced by diseases. Students can visualise, for instance, the changes in the Golgi apparatus due to spinal muscular atrophy or the variances in CFTR expression in cells with CFTR mutations. This interactive approach significantly enhances students' understanding of tissue structure-function relationships and diagnostic skills.

In another ISE students learn how to collect and analyse data from imaging experiments using the fluorescent mitochondrial membrane potential indicator TMRE. The images used within this ISE were obtained from fibroblasts of healthy individuals and patients with a lysosomal storage disorder. Students quantitate fluorescence intensity from mitochondria in regions of interest they choose and students learn about experimental design, application of statistics, as well as the broad changes in cell physiology caused by lysosomal dysfunction.

Using ISE means that our students can study asynchronously and remotely. In one such remote experiment, students measure cell proliferation or cell migration after pharmacological treatments they decide on. The experiment is running live at the OU campus in Milton Keynes, and students access the instrument remotely for their data collection.

Presentation of work carried out using these ISEs is integral to assessment in teaching modules, allowing for authentic assessment. The individualised data enables the re-use of assessment in successive presentations of a module with reduced concerns about plagiarism.

Although online microscopy does not replace the hands-on experience of using a microscope, our students appreciate that the ISEs are based on real data and allow them to participate as researchers in a laboratory through designing experiments, collecting information and producing reports.