The use of a hypo-osmotic swelling (HOS) test on sperm of the pig (Sus scrofa domesticus), emu (Dromaius novaehollandiae), Asian elephant (Elephas maximus), hamadryas baboon (Papio hamadryas hamadryas), and central rock rat (Zyzomys pedunculatus).

A hypo-osmotic swelling test using TALP-HEPES medium over a range of 50 to 300 mOsm/kg was applied to sperm from domestic and endangered species. Maximal responses of curling of the sperm tails were seen over a range of osmolalities for epididymal sperm from the pig (100 mOsm/kg), hamadryas baboon (range 50-125 mOsm/kg), and central rock rat (range 50-100 mOsm/kg), and the ejaculated sperm from the emu (50 mOsm/kg) and the Asian elephant (range 75-150 mOsm/kg). A solution of TALP-HEPES medium at 100 mOsm/kg would be suitable to obtain the maximal response in this range of mammals tested, though it would need to be diluted to at least 50 mOsm/kg when testing the viability of the emu sperm.

Development of an immunoassay to measure progesterone using printed biosensors, and its application to the assessment of ovarian function in the numbat (Myrmecobius fasciatus).

A biosensor system was developed to measure progesterone levels in the urine of female numbats (Myrmecobius fasciata) as an index of ovarian function. Screen printed sensors were coated with a monoclonal progesterone antibody, and incubated in a mixture of sample/standard and progesterone-3-CMO-horseradish peroxidase (HRP). The difference in potential between the working and reference electrode was measured, after exposure to an HRP substrate. EIA and biosensor standard curves showed parallelism, and the biosensor gave values similar (r = 0.83) to the conventional EIA. Progesterone concentrations at different stages of the oestrus cycle were not significantly different to those obtained by EIA.

Maximum rates of cooling by three programmable freezers, and the potential relevance to sperm cryopreservation.

Maximum rates of cooling for the Asymptote EF 100 and the Cryologic CL8800 temperature controller with either a standard or fast chamber were determined and viewed in the context of sperm cryopreservation. All three systems use liquid nitrogen to cool the plate or chamber which would hold the sample, opposed by a variable amount of heat from an internal heater. Maximum rates of cooling for all systems were a function of the temperature gradient between the liquid nitrogen and the plate/chamber and at a plate/chamber temperature of 15 degrees C were 16.5 degrees C/min, 13.3 degrees C/min and 8.0 degrees C/min for the Asymptote EF100, Cryologic fast and slow chambers respectively. These machines are not suited to the freezing of sperm from species requiring rapid rates of cooling, an important consideration when planning to purchase a piece of equipment for this application, and scientists are advised to discuss specifically their requirements with prospective suppliers.

The benefits and limitations of the sperm quality analyzer IIB in assessing porcine sperm motility.

The Sperm Quality Analyzer (SQA) IIB, a member of the SQA-II family of machines which uses the scatter of light by sperm as an indicator of sperm motility, was systematically evaluated as a means of analyzing objectively the motility of porcine epididymal sperm. The sperm motility (%) and the Sperm Motility Index (SMI) are calculated by the machine using pre-programmed algorithms designed for human sperm. The machine performed well and was able to detect changes in sperm motility under experimental conditions. However, two major limitations of this machine were identified, (i) the readings obtained were influenced by the concentration of the sperm suspension despite the actual sperm motility remaining constant, and (ii) the machine was unable to differentiate between progressive and non-progressive motility. It should therefore be recognized that (a) the sperm concentration must be kept constant in studies in vitro if differences between treatment groups are to be identified, and (b) the inability to separate progressive motility from that of total motility will restrict the usefulness of this and similar machines to studies monitoring changes in total motility alone.