Bovine Semen Buffering Capacity and Spermatozoan Acid Tolerance
Key Units: Reproductive Physiology, Biochemistry
Jeffrey Weld,University of Iowa
In the course of investigating reproductive physiology, the generation of spermatozoa and their accompanying semen involves the contributions of the bulbourethral and prostate glands, one constituent of which is the buffering alkali bicarbonate. This investigation allows students to determine the potency of these buffers in serial dilutions of fructose solution, using semen from the straws collected for artificial insemination from the bulls of cattle breeders.
Safety Considerations: Avoid spills and notify instructor of spills.
- 1 straw of frozen bull semen (contact local cattle breeder for old straws still viable- in liquid nitrogen)
- 1 bottle of 1M HCL
- depression slide and cover
- dimple tray for serial dilutions
- stock supply of 10% fructose solution
- 1 ml plastic pipettes
- pH strips, or probe
- Students are to prepare serial pH dilutions of the fructose solution ranging from pH of 1 (one) to 8 (eight) using drops of HCL, stock fructose, and dimple trays
- Spermatozoa motility should first be observed without treatment with the
solutions to establish a "baseline" acitvity level from which to compare
- fresh slides of a drop of bull semen thoroughly stirred with a drop of
pH- adjusted fructose solution should be prepared, then viewed
microscopically for sperm activity
- Students are asked to determine the pH at which sperm activity ceases,
as an indication of buffering capacity of the semen.