No abstract

Urine was collected from numbats (Myrmecobius fasciatus) held at the Perth Zoo (Western Australian) as part of the native Species Breeding Programme which breeds animals in captivity to by released to the wild. Osmolality and creatinine concentrations were very variable despite the provision of water ad libitum and a controlled diet. Progestogen was normalised by dividing the concentration by both the creatinine concentration and the osmolality of the urine. The correlation of these two ratios was highly significant for 7 of the 9 animals.

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.

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.

A biosensor system using screen printed sensors was developed to measure progesterone as an index of ovarian function, and compared with a standard enzymeimmunoassay (EIA). The sensors were coated with a monoclonal progesterone antibody which cross-reacts with a wide range of progestogens, and incubated in a mixture of sample/standard and progesterone-3-CMO-horseradish peroxidise (Prog/HRP). The endpoint was the change in potential read following the addition of sodium perborate. The assay was optimised in terms of the Prog/HRP concentration, the antibody dilution and incubation times. It was then used to measure progestogen in the urine of five female Numbats (Myrmecobius fasciata). Results were available using the sensors within 20 min compared with the standard EIA protocol of 2 h. The serial dilution of a urine sample taken at the diestrus stage showed parallelism with the serially diluted standard. There was a significant rise in progesterone (mean ± sem) after mating compared with that seen before for both the EIA (1.31 ± 0.20 to 3.70 ± 0.13 ng/mL) and the sensor (1.83 ± 0.33 to 4.02 ± 0.61 ng/mL), and there were no significant differences between the sensor and EIA results at either stage (all P > 0.1). A comparison of the values obtained with the sensors to those obtained with the conventional EIA showed a significant correlation for each of the animals (r = 0.82 to 0.99). It is concluded that the biosensor system is a viable alternative to conventional EIA, and provides the advantage of (a) a shorter assay time and (b) greater potential for use in the field.