USE OF A NITROGEN MUSTARD DERIVATIVE IN FIXATION FOR ELECTRON MICROSCOPY AND OBSERVATIONS ON ULTRASTRUCTURE OF TETRAHYMENA

The ultrastructure of the ciliated protozoan Tetrahymena pyriformis has been studied from thin sections of cells fixed with a mixture of glutaraldehyde and tris-(1-aziridinyl) phosphine oxide. Some improvement in fixation has been obtained compared with results employing other fixatives in common use. The fine structure of coated pits, peroxisomes, mucocysts, nuclear pores, cilia, basal bodies, and fibrillar elements are described. Of particular interest are the cilia, nascent kinetosomes in the oral area, and the fine filamentous reticulum of the oral apparatus. These and other observations are discussed in relation to previous descriptions and possible functional significance. © 1968 Academic Press, Inc.