The failure to separate human X-and Y-spermatozoa by the millipore filtration technique.

: Millipore filtration of motile human spermatozoa with the use of a pore size of 5 micrometer without applying high or low pressure results in a small but statistically significant increase of Y-spermatozoa in the filtrate. Immobilized spermatozoa do not pass through the membrane.