Capillary-loaded particle fluid dynamics: effect on estimation of sperm concentration.

Capillary loaded chambers are frequently used for semen analysis. Poiseuille flow of specimen into these chambers causes migration of suspended particles or cells in a direction transverse to the flow, which results in their preferential accumulation in the Segre-Silberberg (SS) planes. This SS effect depends on the transverse velocity gradient in the laminar flow.

Particle distribution in low-volume capillary-loaded chambers.

Accurate determination of sperm concentration in fluid suspension is a critical component in a semen analysis. Inaccurate estimations can lead to misinterpretation of the spermiogram and, in the case of livestock production, can lead to faulty insemination doses, which can adversely affect stud power, fertility, fecundity, and cost effectiveness of breeding programs. Capillary-loaded slides, like the hemacytometer, have been the standard for calibration of other concentration estimation modalities such as photometry, Coulter counter, flow cytometry, and computer-automated semen analysis (CASA).