Figure 2: Determination of basal ciliary beat frequency (CBF). (a) Scanning electron microphotography of ciliated epithelial cells in culture. (b) Power spectrum of ciliary activity obtained from a ciliated cell in culture with a CBF peak of 13.5 Hz. (c) Distribution of basal CBF in cultures of human adenoid epithelium. Basal CBF follows a Gaussian distribution. 44.4% of the cells have a basal CBF between 10 and 12 Hz.