Evaluation of sperm selection efficiency in abnormal semen sample using rheotaxis-based microfluidic device

Semen samples contain a heterogeneous population of spermatozoa, some of which may possess the attributes necessary for successful fertilization. There are several sperm selection techniques that are available for selecting spermatozoa for use in various assisted reproductive technologies (ART). Many reproductive clinics use the conventional density gradient centrifugation techniques to select sperm. These methods are quick and easy to carry out. However, a relatively high centrifugal force can generate reactive oxygen species (ROS). We have developed a rheotaxis-based microfluidic device that washes out the raw semen sample from any dead or less motile sperm. The device consists of a collection and waste chamber. To evaluate the effect of the shape and height of the collection chamber, we measured the sperm motility and velocity parameters after sorting using varying the shape and height of the collection chamber. We verified experimental results using COMSOL simulation, enabling us to assess the importance of the shape and height of the collection chamber in sorting mechanism. Based on the analyses for sperm distribution in the collection chamber, we were able to select sperm with high motility.