Primary cilia in cultured mammalian cells: detection with an antibody against detyrosinated alpha-tubulin (ID5) and by electron microscopy.

A fluorescent-labelled antibody against detyrosinated alpha-tubulin, ID5 (Wehland and Weber, 1987), allows primary cilia and centrioles to be detected rapidly and accurately for analysis in cell cultures. Many features of primary cilia have been re-examined, including frequency of expression in relation to levels of confluency, different sera, different cell cycle stages, and following trypsinization and centrifugation procedures. The detection of multiple ciliation per cell, and the precise positioning of cilia in cells in monolayers are readily recorded. The findings are discussed in relation to cilium expression in cell growth and cycling, to previous findings based on ultrastructural analysis, and to their potential role in sensing the local environment.