Cryotop is one of the best effective methods for oocytes cryopreservation. When Cryotop is inserted into liquid nitrogen

the cooling speed is extremely high

which is difficult to measure by conventional method. In this study

digital oscilloscopes and type T thermocouple of 25 μm diameter were employed to establish a high speed temperature measurement system. The cooling rates of Cryotop device at different carrier material

thickness and cold source temperature were measured. The results showed that when 60μm copper was used as carrier and slush nitrogen was used as cold source

the cooling rate was increased. It could reach 37130 ±1336 K/min

which was twice higher than that of commercially available Cryotop (11982 ± 1936 K/min).