Rapid freezing and vitrification using sucrose are two simple and cost-effective sperm cryopreservation methods. However, it is still unclear which method is better and what the optimal concentration of sucrose is. This study aimed to determine the optimal sucrose concentration for human sperm cryopreservation and compare the cryoprotective effects of rapid freezing versus vitrification using different closed straw systems in terms of sperm motility and DNA integrity. Our data showed that: (1) The optimal sucrose concentration for vitrification was 0.25 mol/l among the tested 0, 0.125, 0.25 and 0.5 mol/l concentrations; (2) Sperm total motility and progressive motility were cryopreserved significantly better by rapid freezing than vitrification in standard 0.5 ml cryostraws (P < 0.05); and (3) Sperm total motility and progressive motility were cryopreserved significantly better by vitrification in the straw-in-straw system than rapid freezing in the standard 0.5 cryostraw (P < 0.05), but no difference was found in sperm nuclear DNA fragmentation level between the two cryopreservation methods (P > 0.05). It was concluded that sucrose at 0.25 mol/l concentration is suitable for human sperm rapid freezing and vitrification, and sperm cryopreservation can be achieved by rapid freezing using closed standard 0.5 ml straws or by vitrification using the novel straw-in-straw system made of standard 0.25 and 0.5 ml straws.

使用蔗糖的快速冷冻和玻璃化冷冻是两种简单且经济高效的精子冷冻保存方法。然而，目前尚不清楚哪种方法更好以及蔗糖的最佳浓度是多少。本研究旨在确定人类精子冷冻保存的最佳蔗糖浓度，并在精子活力和 DNA 完整性方面比较使用不同封闭吸管系统的快速冷冻与玻璃化冷冻保护效果。我们的数据表明：（1）在测试的 0、0.125、0.25 和 0.5 mol/l 浓度中，玻璃化的最佳蔗糖浓度为 0.25 mol/l；(2) 与玻璃化冷冻相比，在标准 0.5 ml 冷冻管中冷冻保存精子的总活力和进行性运动的效果明显更好（P < 0.05); (3) 吸管系统玻璃化冷冻保存精子的总活力和渐进运动能力明显优于标准0.5 冷冻管的快速冷冻（P  < 0.05），但精子核DNA片段化水平无差异两种冷冻保存方式（P  > 0.05）。结论0.25 mol/l浓度的蔗糖适用于人类精子的快速冷冻和玻璃化，精子冷冻保存可以通过使用封闭标准0.5 ml吸管进行快速冷冻或使用由新型吸管制成的吸管系统进行玻璃化来实现。标准的 0.25 和 0.5 毫升吸管。