An improved method of sperm selection by glass wool filtration

An improved method of sperm selection by glass wool filtration is introduce d. After incubation of glass wool filtrates for 30 min at 37 degreesC in a conical-shaped 1.5-ml tube, an enrichment of highly motile spermatozoa was found in the bottom laver of the tube. The effect turned out to be dependen t on the conical shape of the tube, as it was not observed in flat-bottomed tubes. Native ejaculates (obtained from 30 men) and their glass wool filtr ates were analysed by cell counter, co mputer- assisted sperm-motility anal ysis, morphological differentiation and supravital staining of spermatozoa. When 400 mul of ejaculate., diluted with 800 mul of medium, was applied to the top of a column consisting of a 1-ml disposable syringe barrel gently packed with 15 mg of glass wool to a depth of 6 mm, an enrichment of viable spermatozoa was found in the first three 100-mul fractions taken from the bottom of the tube. It is the simplicity of this technique that makes it so easily applicable.