Laser light-scattering studies of bull spermatozoa. I. Orientational effects

Abstract

Calculations based on the known dimensions of bull spermatozoa show that the scattered light intensity is strongly dependent upon the relative orientation of the particle to the incident beam. The magnitude of this effect of apparently much greater than for other systems where motility has been investigated by dynamic light scattering. The calculations show that the scattering source can be approximated by a small spinning mirror, and consequently the greatest light intensity at the detector results from cells swimming in a direction perpendicular to the scattering vector. The calculations are in substantial agreement with photographic observations, as well as direct measurements of the scattered intensity. Previous treatments of dynamic light scattering from swimming bull spermatozoa based on point scattering models are shown to be incorrect.

Laser measurement of the motility of bull spermatozoa in an egg-yolk diluent

“…In the typical correlation time of our data (<2msec) a spermatozoon will rotate through less than 1/40 of one cycle in moving forward <200nm. Diffraction due to the shape of the head, which is large compared with the wavelength of laser light employed (632-8 nm), may also affect the autocorrelation of scattered laser light (Craig, Hallett & Nickel, 1979;Harvey & Woolford, 1980). Despite these complications these results and those reported by others (Dubois et al, 1975;David et al, 1978) closely approximate a Lorentzian-type autocorrelation :…”

Twin-beam laser velocimeter for the investigation of spermatozoon motility

“…Most motile micro-organisms, however, are of appreciable size and have an asymmetrical shape. In particular, bull sperm have large flat heads and are visible only if they swim in or near the plane perpendicular to the scattering vector (Harvey and Woolford, 1980). As they are also constrained to swim in a plane perpendicular to the incident beams in our apparatus, the bull sperm will be visible only in a small range of directions, 0, on either side of the line that is the intersection of this plane with the plane perpendicular to the scattering vector.…”

“…In the case of bull spermatozoa and other cells that are large and flat (when compared with the wavelength of light) such an analysis is completely inadequate because the scattered light seen by the detector arises almost totally from the cells swimming in a direction perpendicular to the scattering vector and the intensity fluctuations in the scattered light depend only upon the rotational frequency of the swimming cells (Craig et al, 1979. Harvey andWoolford, 1980). This phenomenon (which also occurs with other mammalian cells, notably ram spermatozoa) enables the rotational frequency of the cells to be extracted from the spectrum of the intensity fluctuations if the swimming motion is adequately modeled in the theory, and this may well be a useful measure of the vigor of the swimming population.…”

A thermal study of cellular motility by optical time-resolved correlation

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Such methods have become increasingly sophisticated with improvements in image analysis and computing. Indeed, from simple techniques such as "Passage Counting," 1 which involves microscopic observation of the number of spermatozoa crossing a defined line or area on the field of view in a given period, to more elaborated methods such as photon correlation spectroscopy, 15,16 where swimming speed distribution is reconstructed from the correlation data by Stocks method of splines, ingenious techniques have been proposed to evaluate the spermatozoa kinematics.…”