Studies investigating the interaction of Candida with a single host cell type such as phagocytes or epithelial cells are typically performed in vitro. The advantages of in vitro studies include the ability to compare multiple conditions in one experiment, the ability to perform thorough biochemical and immunologic analyses, the relatively short duration of experiments, lower experimental costs, and the ability to reduce the use of laboratory animals. The major disadvantage of in vitro experiments is that it is not possible to fully replicate the myriad of cellular and extracellular signals provided by the host environment. Several animal models of candidiasis are regularly used, including models of oropharyngeal, vaginal, and disseminated candidiasis. Information about the interaction of specific host cell types with Candida organisms in vivo can sometimes be obtained through conventional histology or immunohistochemistry, but these analyses require sacrifice of the animal and thus are often limited to a single time point during the course of infection. Several fluorescent proteins have recently been codon optimized for expression in yeast. The authors suspect that any strain of Candida that has relatively bright fluorescence could be used in this model. For imaging, an inverted confocal microscope with an enclosed stage incubator chamber and generic stage insert is used. Recently, a stage insert was constructed allowing the use of an Olympus FV1000 laser scanning confocal microscope at the confocal microscopy core facility. Images were successfully obtained using both 10x, 0.4to 0.45-numerical-aperture and 20x, 0.75-NA dry objective lenses.