Isolation and analysis of cilia fraction from ARPE-19 cells. (A) Western blot to show levels of acetylated tubulin, I-2, PP1C and actin in equal numbers of sub-confluent and confluent cells used to isolate a cilia fraction. (B) Sub-confluent and 48 hr post confluent cells were used in parallel for cilia isolation by Calcium Shock and ultracentrifugation. Equal volumes of the cilia fraction were analyzed by SDS-PAGE in 12% gels stained with Commassie. (C) Western blotting to show the presence of I-2, PP1C and acetylated tubulin in the cilia fraction of sub-confluent cells and cells harvested 48 hrs after confluence.