Abstract: The invention relates to a sterile, disposable, compartmentalized Zavos swim-up column for the swimming-up of spermatozoa, at desired levels of dilution in a media, and a swimming down of spermatozoa into compartments within the column, as well as to a method for the harvesting of those semen samples having particular sperm morphology, motility, progressive motility, speed, sperm concentration, fertilization potential, and a sex ratio. The device comprises a hollow, vertically supported column, having a closed lower end, and an open upper end. A lowermost or first conical member is arranged at the lowermost end of the column, the lowermost conical member having a lowermost periphery in sealing engagement with the bottom of the column. The first conical member has inclined side walls and a truncated uppermost portion defining a peripheral edge which is open within into the column.