Storage & Handling of Frozen Semen
In the graphs below, pay attention to the 0.5 ml French straw data with the solid red lines.
Examine the first graph. If a straw is removed from liquid nitrogen and held in ambient temperature for various periods of time before thawing in a water bath, post-thaw motility of sperm declines after just 0.5 minutes (30 seconds) to 1 minute of exposure.
Examine the second graph. The temperature of the semen in the straw when held for 30 seconds in the air was -170°C and still -140°C when held for 1 minute. Even though the temperature was still very cold and the semen remaining frozen, damage was occurring to the sperm.
The results shown in these two graphs should emphasize how important it is to be careful when handling semen in a liquid nitrogen tank. You need to know what you want, where it is in the tank and then quickly remove and thaw what you need.
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