A quasi-elastic light scattering and cinematographic investigation of motile Chlamydomonas reinhardtii.

Quasi-elastic light scattering and cinematographical techniques were used to investigate the motility of Chlamydomonas reinhardtii (wild type). It was found that quantitative information on the trajectory of motion was required for a meaningful interpretation of the autocorrelation functions. Two models for describing the oscillatory motion of the cell were developed; one based on the instantaneous forward-and-backward motion of the cell, and the other based on a sinusoidal perturbation to the average forward motion. Both models gave satisfactory agreement with the shape of the experimentally measured autocorrelation function, thus making it possible to use this measurement to determine mean progressive swimming velocities in a population of greater than 200 cells.