Answer from: Peter Hura
This question always comes up with the connection of the survival of biological material. What needs to be known from the beginning that the temperature of survival is different for different kinds of materials. The lowest temperature rate that is acceptable for survival is different for oocytes, embryos, and sperm. However, there is some general temperature rate that suitable for all of them. It is minus 180 Celsius. However, all tanks for transportation of biological material are created for keeping a constant survival temperature during the transportation of around minus 190-196 degrees Celsius, for some period of time mentioned by the producer.
The temperature rate around minus 180 degrees Celsius in such tanks indicates that the tank has started losing its liquid nitrogen vapor. This is an urgent signal for the shipping company that samples need to be delivered to the final destination as soon as possible or the tank must be charged additionally. The best option to ensure that nothing bad might happen with the temperature during the transportation is to build a logistic with consideration of the maximum temperature holding tank with the rate of minus 190-196 degrees Celsius.
The main thing is using fully calibrated tanks and data loggers with the possibility to record temperature during the whole trip. And, last but not least, all those devices must be tested before loading the samples t the tank.
