The yeast is incubated in horse serum at 37oC for 2 hours and the cells examined microscopically. Candida albicans, and the rarer oral pathogen C. dubliniensis, are the only species of the genus Candida that produce a short germ tube under these conditions as seen in the figure. C. albicans represents 80% of all clinical isolates. Other species of the genus Candida are germ tube-negative and require further tests to identify them.
