Binding of spermatozoa to positively charged beads as an inexpensive method to isolate sperm heads and tails

Rat epididymal spermatozoa were capable of rapid binding to various positively charged beads, but not to beads with negative or no charge. The binding appeared to involve the end-piece and perhaps a portion of the tail. The binding was quite resistant to acid, heat, Triton X-100, sodium dodecyl sulphate and trypsin. The bound spermatozoa could be slowly released from the beads in a concentrated solution of salts, the best among these tested was 1 M-ammonium acetate. The bead-binding property of the spermatozoa was employed to develop, a new, simple and inexpensive method to isolate heads and tails without the use of an ultracentrifuge. The yield of the heads from spermatozoa of the cauda epididymis was 65 to 80% with 2 to 10% of tails contaminating while the yield of the tail was 30 to 40% with no cross contamination.