Ultrastructure of the zoosporangia of Albugo ipomoeae-panduratae as revealed by conventional chemical fixation and high pressure freezing followed by freeze substitution.

Both conventional chemical fixation and high pressure freezing followed by freeze substitution (HPF/FS) were used to prepare zoosporangia of the oomycete Albugo ipomoeae-panduratae inside infected host leaves for study with transmission electron microscopy. Both fixations gave good preservation of ultrastructural details and data from the two sample types were highly complementary. However, HPF/FS gave better overall specimen contrast and superior preservation of microtubules, basal bodies and curved vacuoles closely associated with basal bodies.