Ultrastructure of Ciliary Microtubules after Critical Point Drying

Many studies have been conducted on the fine structure of the "9 + 2" microtubules from cilia and flagella . The techniques used include both thin sectioning of whole cilia or flagella and negative staining of isolated microtubules . In this study, cilia from four diverse species of ciliate protozoa : Euplotes eurystomus, Spirostomum ambiguum, Tetrahymena pyriformes, and Colpoda ; and sperm from the insect Oncopeltus fasciatus, were prepared by spreading on a Langmuir trough (12) followed by drying from liquid CO 2 (2) . The combined procedures (5) will hereafter be referred to as LTCD . In each case, small spherical periodic masses occur attached to one of the doublet peripheral microtubules (11) .