Better Biology loves this lab. It gives students as close to the real experience they would experience if actually performing the Gram stain technique. The virtual lab requires them to follow procedure steps precisely in order to obtain positive results. Whether used to augment the study of cells or used as part of a microbiology unit, the virtual lab is a great tool. Better Biology has used the lab, both as an in-class discussion and activity, as well as a graded hw, after introduction during a class period. It is editable and gives the opportunity to circle back to kingdoms, eukaryotic vs. prokaryotic cells and reinforcement that prokaryotic cells have plasma membranes.
The pre-lab section, "Before you begin --> Engage your Brain" draws students in as they study diagrams of bacterial cell walls and makes inferences as to their similarities and differences. Students are also introduced to the steps required to stain and counterstain the bacteria. Questions are included in both the pre-lab and post-lab section.
Google doc link included for easy editing and customization.