Physical and Chemical Properties of Cilia Isolated from Tetrahymena pyriformis*

SYNOPSIS. Cilia devoid of their basal granules and isolated from Tetrahymena pyriformis strain W, by the method of Watson et al. (66) have been characterized in terms of physical, chemical and immunologic properties. The general chemical composition of cilia, based on mean values from these determinations is 66.3% protein, 24.3%“lipid,” 3.7 or 4.8% carbohydrate, and 0.4% nucleic acid. The amino acid composition of cilia includes hydroxyproline and is not significantly different from the amino acid composition of whole cells. Chloroformmethanol extracts of ciliary material contain free amino acids as well as neutral lipids and phospholipids. The lipid composition of cilia also is not significantly different from that of whole cells. Pentose, hexose and small but significant amounts of adenine nucleotide and ribonucleic acid are present. Cilia are a greater stimulus for the production of antibody than an equivalent amount of cellular antigen, and the ciliary antigen is strain specific.