Digital whole slide technology has been transforming teaching in histology and histopathology since the early 2000s. Virtual slides, or Whole Slide Images (WSIs) are created when glass slides are digitally scanned either in their entirety at x10 or x40 magnification or a set region at a higher magnification (x100).
Virtual slides allow you to navigate a tissue section, just as you would under the microscope, zooming in/out and panning across. However, the burden of adjusting the focus across the slide and when changing lenses is removed for virtual slides.
Digitising the process of viewing tissue sections has revolutionised access to this important learning resource. Students are no longer limited to their class slide set, and to the availability of glass slides and microscopes. Cloud-based whole slide repositories, such as our own Slice repository, now provide students with the opportunity to access these precious resources at home, and academics with the chance to share teaching slides across institutions.
The file size for a virtual slide can range from approximately 1 GB to up to 23 GB depending on the file format, the area scanned and the magnification the slide is scanned at. Prior to the use of cloud-based servers sharing these large files was difficult. Instead of having to download the image in its entirety, Slice breaks these images down into smaller tiles. When viewing, panning across and zooming in and out on an image, only the tiles viewed are downloaded, reducing the overall download during the session.
Digitising the glass slide has also provided the opportunity to annotate slides well beyond the clumsy possibilities of the permanent marker. This has opened up many new ways of
using whole slides in learning activities, both within and outside the classroom.
Students viewing a virtual slide in a classroom activity.