The chapter, "Karyotype analysis of murine macrophages for undergraduate students" was written by the listed authors including Lynette B. Sigola (Douglas College Faculty). We have developed a karyotype analysis laboratory involving photomicroscopy which is suitable for use by students in biology courses at the undergraduate level. The laboratory activity uses the murine macrophage RAW 264.7 cell line maintained in vitro. In this laboratory activity, students benefit from an introduction to conditions required for cell culture (media, growth conditions, sterile technique), and use an inverted microscope to observe live cells in culture.
We describe the use of colchicine to arrest dividing cells in metaphase when chromosomes are most condensed. Cells are then harvested, treated in a hypotonic solution, fixed, and then dropped onto glass microscope slides. The slides are then stained and mounted and sealed. Photomicrographs are taken for analysis. We discuss the significance of cell preparation for microscopic analysis in engaging students as active learners.
The chapter, "Study of cell form and function through microscopy: Macrophages in action for undergraduate students" was written by the listed authors including Lynette B. Sigola (Douglas College Faculty). Microscopy at the undergraduate level can be pursued over a wide range of activities, from a relatively passive experience where students use microscopy to look at prepared slides to record their findings in the form of sketch diagrams, to inquiry-based labs, where students learn to appreciate many dimensions of observation and discovery through microscopy. The laboratory activity we describe here, stemmed from our research on mechanisms of fungal recognition and phagocytosis of a murine macrophage cell line. Phagocytosis of zymosan particles (cell wall derivatives of the yeast Saccharomyces cerevisiae) by macrophages can be easily quantified, using a compound microscope, by counting the number of cells ingesting zymosan as well as the number of particles ingested by each particular cell. Phagocytosis can be assessed after different pre-treatments of both particles and macrophages, involving students in qualitative and quantitative data analysis. Furthermore, this research-inspired microscopy laboratory activity exposes undergraduates to many aspects of research, ranging from technical and logistical skills to ethical aspects of scientific inquiry.
