A combined interactive online simulation and face-to-face laboratory enable undergraduate student proficiency in hemocytometer use, cell density and viability calculations.

A hemocytometer is a key piece of laboratory equipment typically used in diagnostic and immunology research laboratories to enumerate white blood cells. The accurate quantification of cell density is essential to ensure accurate numbers of cells are added to assays to generate valid data. Hence, learning to correctly use a hemocytometer is a critical skill for all undergraduate immunology students. However, this skill can be challenging to learn because of students' unfamiliarity with correct cell identification, differentiating viable versus dead cells and mathematical proficiency in calculating cell density and viability. To address these issues, we developed an interactive computer simulation that replicated all aspects of a Neubauer-style hemocytometer. This simulation was used to teach second-year undergraduate immunology students before a face-to-face (F-2-F) laboratory exercise where these skills were applied. Using a mixed methods approach, student performance and feedback were collected on broad aspects of the intervention and its benefits to the F-2-F setting. The approach was found to be extremely successful with all measures indicating a significant impact of the virtual hemocytometer on student learning, understanding and confidence. We suggest that integrating an online simulation to teach students the fundamentals of hemocytometer use and calculations is a valuable educational aid for learning this important skill.