Fig. 1. Methods for recording ciliary beating frequency (CBF). (A) Pedal ciliated epithelial tissue is removed from the foot margin of Tritonia diomedea and dissected to small pieces with vigorously beating cilia, accessible for experimentation. (B) Phototransducer measurement of a video projection of beating cilia produces an oscillatory voltage output corresponding to the ciliary beating rate. (C) Using a Fast Fourier transform the dominant frequency from the voltage signal can be measured.