Attempted sexing of bovine spermatozoa by fractionation on a Percoll density gradient

Bovine spermatozoa were fractionated on Percoll density gradients into two major subpopulations of motile spermatozoa and a minor fraction containing mostly nonmotile spermatozoa with abnormal morphology. Fractionation required the addition of bovine serum albumin and a continuous Percoll gradient buffered with sodium bicarbonate. It is postulated that, under suitable ionic conditions, the binding of bovine serum albumin to spermatozoa amplifies subtle differences between subpopulations. These studies were directed toward separating Y- and X-bearing spermatozoa. However, when the subpopulations were evaluated by flow cytometry, their Y:X ratios were similar to that of an unfractionated control.