Further optimization of mouse spermatozoa evaporative drying techniques

Abstract

It has been shown in the past that mouse spermatozoa could be dried under a stream of nitrogen gas at ambient temperature and stored at 4 °C or 22 °C for up to 3 months and was capable of generating live-born offspring. In previous desiccation work, dried sperm were stored in a vacuum-sealed plastic bag placed in a vacuum-packed Mylar bag. However, dried specimens stored in this way often lost moisture, particularly in samples stored at higher temperatures (22 °C) compared to lower temperatures (4 °C). The present report describes a method which minimizes this water loss from the dried sperm samples. Its use is described in a preliminary study on the effect of supplementing the trehalose with glycerol. The results have demonstrated that mouse sperm can be stored at 4 °C over saturated NaBr without the uptake of water which occurs when they are stored in Mylar packages. In addition, we were able to get some survival of sperm (9–15%) at room temperature storage after 3 months. The addition of glycerol to trehalose had little effect on the survival of dried mouse sperm stored over NaBr for 1 and 3 months.