影响玻璃化冷冻兔胚胎效果的一些因素

试验对影响玻璃化冷冻兔胚胎效果的一些因素进行探讨，以找出理想的玻璃化冷冻方法。在测试的５种玻璃化溶液中，含３５％乙二醇（ＥＧ）和１．０ｍｏｌ／Ｌ蔗糖的溶液（ＶＳ１）对胚胎的毒性最小。用ＶＳ１冷冻桑椹胚和囊胚的理想程序是：在室温下使胚胎分别在２０％ＥＧ和３５％ＥＧ中平衡２、３分钟后，移入ＶＳ１中，０．５分钟内（囊胚也可在２分钟后）投入液氮中冷冻。桑椹胚的存活率为９１．７％（３３／３６），囊胚的存活率为９７．１％（３３／３４）～９７．３％（３６／３７）。８～１６细胞胚胎的理想冷冻程序为：在室温下使胚胎在２０％ＥＧ、３５％ＥＧ中平衡２、３分钟，移入４℃的３７％ＥＧ＋１．０ｍｏｌ／Ｌ蔗糖溶液中平衡２分或１０分钟后冷冻，胚胎存活率分别为１００％（３７／３７）、８６．１％（３１／３６）。     

扩张囊胚玻璃化超低温冷冻保存及移植技术的研究

本试验探讨了对鼠扩张囊胚玻璃化冷冻保存后，提高发育率的最佳条件。玻璃化溶液是用ＰＢＳ液稀释成的３０％聚蔗糖＋０．５Ｍ蔗糖混合法，再将乙二醇（ＥＧ）调制成２０、３０及４０％（ｖ／ｖ）的溶液，即ＥＦＳ２０、３０及４０。玻璃化冷冻保存是１０、２０及２５℃温度下，将扩张囊胚直接移入ＥＰＳ溶液后投入液氮中一步法令冻保存，其中２５℃下保存后的发育率最高（８７％）。继之将扩张囊胚用１０％ＥＧ溶液经５分钟处理后，再移入ＥＦＳ４０中二步法冷冻保存，发育率高达９４％。利用二步法冷冻保存的扩张囊胚移植后，妊娠受体的产仔率为６６％（１６８／２５５），同时照组产仔率６１％（８０／１３２）相比无显著性差异（Ｐ＞０．０５）。     

家兔扩张囊胚玻璃化冷冻保存技术的研究

本试验对家兔扩张囊胚的玻璃化冷冻保存技术进行了探讨。首先在２０℃室温下，将扩张囊胚直接移入ＥＦＳ４０溶液中短时间平衡后，直接投入液氮中冷冻保存（一步法）；或胚胎在１０％～２０％ＥＧ（或ＥＦＳ２０）溶液中经预先处理后，再移入ＥＦＳ４０中冷冻保存（二步法），解冻后的胚胎发育率达到９５％～１００％。当室温提高到２５℃时，一步法和二步法冷冻的胚胎均得到了较高的发育率（８９％～９０％）。利用２０℃条件下一步法即２分钟平衡后冷冻的胚胎移植后，妊娠受体的产仔率为２９．２％（７／２４），同对照组产仔率３２．４％（１１／３４）相比无显著性差异（Ｐ＞０．０５）。     

牛体外受精胚冷冻保存的研究

对牛卵泡卵母细胞体外受精（ＩＶＦ）１６８ｈ的致密桑椹胚、囊胚用常规快速冷冻法、预冷和不预冷的超快速冷冻法进行了冷冻保存试验。结果表明：ＩＶＦ囊胚采用含１０％甘油的常规快速冷冻法、含２．１ｍｏｌ／Ｌ甘油和０．２５ｍｏｌ／Ｌ蔗糖预冷５ｍｉｎ的一步冷冻法及含２５％甘油和２５％乙二醇预冷５ｍｉｎ的玻璃化冷冻法等３种方法进行冷冻保存，解冻后的继续发育率（６８．０％，５９．０％，６５．７％）均无显著差异（Ｐ＞０．０５），可用快速、简便、预冷的一步冷冻法或玻璃化冷冻法替代常规快速冷冻法；ＩＶＦ致密桑椹胚可用一步冷冻法（２．１ｍｏｌ／Ｌ甘油＋０．２５ｍｏｌ／Ｌ蔗糖）和玻璃化冷冻法（２５％甘油＋２５％乙二醇或２５％甘油＋２５％１，２－丙二醇）进行预冷的超快速冷冻保存；冻前预冷（５ｍｉｎ）能显著提高ＩＶＦ囊胚的冻后形态正常率和继续发育率（Ｐ＜０．０５）；ＩＶＦ囊胚冷冻—解冻后的继续发育率高于ＩＶＦ致密桑椹胚。     

转基因兔胚胎玻璃化冷冻保存的研究

在２５℃条件下,将兔体外受精精子载体转基因兔桑椹胚置于含有４０％乙二醇、１８％Ｆｉｃｏｌ、０．３ｍｏｌ蔗糖的ｍＰＢＳ溶液（ＥＦＳ４０）中平衡２分钟,然后直接投入液氮,成功地进行了玻璃化冷冻保存。解冻后桑椹胚发育至囊胚和孵化囊胚的比例分别为６５．８１％和３９．２４％,与未经冷冻的鲜胚发育比例（７１．０５％和４３．４２％）相比,没有明显的差异。７８枚经玻璃化冷冻和解冻的桑椹胚移植给５只受体,其中２只妊娠,共产下８只活仔兔。     

脱防冻剂方法对牛体外受精胚胎冷冻后成活率的影响

为了观察脱防冻剂方法对牛体外受精冷冻胚胎在体内、外发育率的影响,应用常规冷冻法在０．７５ｍｏｌ／Ｌ甘油＋０．５ｍｏｌ／Ｌ丙二醇溶液中冷冻受精后７、８ｄ的囊胚,解冻后在０．２５、０．５ｍｏｌ／Ｌ蔗糖液中二步或在０．２５ｍｏｌ／Ｌ蔗糖液中三步脱防冻剂的胚胎孵化率（分别为６８．６％、６２．２％、６８．７％）与用ＰＢＳ／ＦＣＳ六步脱防冻剂的差异不显著（７０．４％,Ｐ＞０．０５）,但在０．５ｍｏｌ／Ｌ蔗糖液中三步脱防冻剂后,孵化率显著降低（４７．６％,Ｐ＜０．０１）。用０．２５ｍｏｌ／Ｌ或０．５ｍｏｌ／Ｌ蔗糖或海藻糖预先使胚胎脱水后冷冻,解冻后可使胚胎直接在ＰＢＳ中一步脱掉防冻剂,胚胎孵化率（４５．０％～４９．５％）与在０．２５ｍｏｌ／Ｌ蔗糖液中二步脱防冻剂的相似（５１．５％,Ｐ＞０．０５）。移植试验表明,在０．２５ｍｏｌ／Ｌ蔗糖液中二步脱防冻剂获得的妊娠率与六步脱防冻剂相似,与在ＰＢＳ中一步脱防冻剂的亦无明显差异,但妊娠率均偏低（２１．４％～３７．５％）。     

BFF,rbGH对牛卵泡卵母细胞体外受精后发育的影响

利用屠宰黄牛卵巢，对２～５ｍｍ卵泡卵母细胞的体外成熟（ＩＶＭ）、体外受精（ＩＶＦ）、受精卵的体外培养（ＩＶＣ）进行了系列研究。结果表明，在成熟培养液中单独添加１０％Ｄ０ＥＣＳ（发情当天牛血清）获得了卵泡卵母细胞受精后较高的卵裂率（６４．７％）、桑椹胚发育率（３９．９％）和囊胚发育率（２４．８％），说明在成熟培养液中单独添加Ｄ０ＥＣＳ是可行的；在含１０％Ｄ０ＥＣＳ的成熟培养液中再添加１０％或２０％ＢＦＦ（牛卵泡液），均能提高受精卵的卵裂率以及桑椹胚和囊胚的发育率，以添加２０％ＢＦＦ效果较好，其囊胚发育率（３５．０％）显著高于对照组（２４．８％，Ｐ＜０．０５）；在卵泡卵母细胞成熟培养系统和受精卵共同培养系统中添加１０μｇ／Ｌ重组牛生长因子（ｒｂＧＨ），虽对体外受精卵的卵裂率无显著影响（Ｐ＞０．０５），但能显著提高卵裂胚的囊胚发育率（Ｐ＜０．０５）     

奶牛胚胎分割与半胚裸露冷冻保存试验

本试验研究了①Ａ、Ｂ、Ｃ三个质量等级胚胎的分割效果；②五种不同冷冻方法冷冻裸露半胚的存活情况；③冻前培养３．０、１．５～２．０、１．０小时的裸露半胚存活率。结果①Ａ、Ｂ、Ｃ级胚胎的分割成功率分别为９５．８％（９２／９６）、７且．４％（７０／９８）、３０％（６／２０），三者间差异极显著（Ｐ＜０．０１）；②半胚冷冻前以２０％ＦＣＳ－ＰＢＳ液培养３．０小时后，以五种不同冷冻方法冷冻，均未获得存活半胚；③半胚冷冻前培养３．０、１．５～２．０、１．０小时后，以添加１０％而聚糖的１０％甘油＋０．１Ｍ蔗糖／ＰＢＳ液冷冻，分别获得了０％（０／４５）、６８．８％（１１／１６）、７５．０％（９／１２）的存活率。结果表明，胚胎质量是影响胚胎分割成功率的关键因素，半胚冷冻前的培养时间是影响裸露半胚存活的重要因素。     

奶牛半胚裸露冷冻保存试验

本试验研究了不同冷冻方法，半胚冷冻前不同培养时间及不同冷冻保护液对奶牛７日龄半胚裸露冷冻效果的影响，结果以１０％（Ｖ／Ｖ）甘油＋１０％（Ｗ＋Ｖ）葡聚糖（Ｔ－５００）＋０．１Ｍ蔗糖＋２０％ＦＣＳ－ＰＢＳ溶液为冷冻保护液，裸露冷冻前培养１．０小时的半胚，获得了８２．４％（１４／１７）的较高存活率。试验结果表明，半胚冷冻前培养时间及不同保护液对奶牛半胚裸露冷冻有显著影响。     

牛体外受精扩张囊胚的玻璃化超低温冷冻保存及移植技术的研究

本试验对牛的扩张囊胚的冷冻保存技术进行了探讨。在２５℃温度下，利用ＥＦＳ４０的玻璃化溶液，将扩张囊胚直接移入此液中平衡后，投入液氨中一步法冷冻保存。或胚胎移入ＥＦＳ４０之前，在１０％ＥＧ溶液中预先处理，二步法冷冻保存。其解冻后获得了较高的发育率（分别为５９％ＶＳ６３％）。冷冻保存的胚胎移植后的妊娠率及产仔率分别高于对照组（８０％ＶＳ５５％；５５％ＶＳ２３％）。     

不同冷冻和解冻方法对小鼠桑椹胚发育的影响

本试验以2种程序化冷冻液和2种玻璃化冷冻液对昆明白系小鼠的桑椹胚进行细管法冷冻保存,比较程序化冷冻-管外解冻和玻璃化冷冻-管内解冻对胚胎体内、外发育的影响。胚胎体外培养结果表明:玻璃化冷冻组及程序化冷冻组胚胎发育率(95.3%￣95.8%,98.9%)无显著(P>0.05)差异。将程序化冷冻、EFS30玻璃化冷冻以及新鲜的胚胎各168枚移植给假孕受体鼠,妊娠受体产活仔率各组间相比(50.8%,58.3%,54.9%)无显著性(P>0.05)差异。结果证明,玻璃化冷冻保存的胚胎管内解冻效果好,为生产中家畜的胚胎移植提供了理论和技术参考。     

Survival Rate and Ultrastructure of Vitrified Bovine in vitro and in vivo Developed Embryos

The capacity of different vitrification media and methods was tested onto in vivo and in vitro produced bovine morula/blastocysts and their ultrastructure and survival studied post-thawing. Two vitrification solutions were finally selected, named 40 ES (40% ethylene glycol in PBS containing 0.5 M sucrose) and 35 EFS (composed of 35% (v/v) ethylene glycol in PBS containing 0.5 M/l sucrose and 30% (w/v) Ficoll 70). The straws were either precooled or not precooled in nitrogen vapour, plunged and stored in LN₂ for 10–25 days, and then thawed in a 20° C waterbath. The content of the straws was rediluted in 1M sucrose solution in PBS and later cocultured with BOEC for 48 h. The overall survival rates for in vitro and in vivo embryos were 36% (12 of 33) and 20% (3 of 15) after 24 h and 21% (7 of 33) and 33% (5 of 15 ) after 48 h. The survival rates for precooled embryos were significantly higher than for not precooled (48% vs 13% after 24 h and 44% vs 4% after 48 h) when tested across vitrification media. The in vitro-produced embryos presented an ultrastructure similar to the pre-freeze state, irrespective of the vitrification media used. The in vivo developed embryos showed a rather modified post-thaw ultrastructure, with clear signs of osmotic changes at both the trophoblastic and embryonic cells. The results indicated that in vitro and in vivo developed bovine embryos can survive vitrification using ethylene glycol as a cryoprotectant.     

Stepwise in-straw dilution and direct transfer using open pulled straws (OPS) in the mouse: a potential model for field manipulation of vitrified embryos

In the present study, mouse blastocysts were employed to investigate the feasibility and efficiency of stepwise in-straw dilution and direct transfer using the open pulled straw (OPS) method. In experiment I, the effects of various vitrification solutions (VS) on embryo survival were examined. After thawing, the expanded blastocyst rates (97.59 and 95.05%) and hatching rates (80.48 and 78.95%) achieved in the EDFS30 [15% ethylene glycol (EG), 15% dimethyl sulfoxide (DMSO), Ficoll, and sucrose] and EFS40 [40% EG, Ficoll, and sucrose] groups were no different from those (96.15% and 83.33%) of the control group. However, the rates in the EFS30 [30% EG, Ficoll, and sucrose] (87.80 and 55.43%) and EDFS40 [20% EG, 20% DMSO, Ficoll, and sucrose] (95.69 and 70.97%) groups were significantly lower than those (96.15 and 83.33%) of the control group (P<0.05). In the experiment II, the effects of the volume of VS in the OPS on the survival of embryos after in-straw thawing were investigated. When the length of the VS in the column was less than 1 cm, the in vitro viability of embryos thawed by stepwise in-straw dilution was no different among the experimental and control groups. The embryos could be successfully thawed by immersing the OPS in 0.5 M sucrose for 3 min and then 0.25 M sucrose for 2 min. In experiment III, the effect of immersion time of the OPS in diluent (PBS) on the viability of vitrified embryos was investigated. After in-straw thawing, OPSs were immersed immediately in 1 ml PBS for 0 to 30 min. When the immersion time of the OPSs in PBS was less than 12 min, in vitro development of the in-straw thawed embryos was no different from that of the controls. In experiment IV, in-straw thawed blastocysts were directly transferred to pseudopregnant mice to examine their in vivo developmental viability. The pregnancy (91.67%) and birth rates (42.42%) of embryos in-straw thawed and directly transferred were no different from those of the unvitrified controls (90.90 and 40%) and embryos thawed by the conventional method (84.61 and 46.94%). These results demonstrate that mouse embryos vitrified with OPS could be successfully thawed by stepwise in-straw dilution and transferred directly to a recipient and that this method might be a model for field manipulation of vitrified embryos in farm animals.     

Vitrification of Boer Goat Morulae and Early Blastocysts by Straw and Open-Pulled Straw Method

The aim of this study was to investigate the effects of different vitrification solutions [EFS30 or EFS40 contains 30% (v/v) ethylene glycol (EG), 40% (v/v) EG; EDFS30 or EDFS40 contains 15% (v/v) EG and 15% (v/v) dimethyl sulfoxide (DMSO), 20% (v/v) EG and 20% (v/v) DMSO], equilibrium time during vitrification (0.5-2.5 min) and vitrification protocols [one-step straw, two-step straw and open-pulled straw (OPS)] on in vivo development of vitrified Boer goat morulae and blastocysts after embryo transfer. In the one-step straw method, the lambing rates of vitrified embryos in EFS30 (37.5%), EFS40 (40.5%) or EDFS30 (38.2%) group were similar to that of fresh embryos (57.5%) and conventional freezing method (46.7%) when the equilibrium time was 2 min. In the two-step straw method, the highest lambing rate was obtained when embryos were pretreated with 10% EG for 5 min and then exposed to EFS40 for 2 min (51.4%), showing similar lambing rates compared with fresh embryos (56.1%) or the embryos cryopreserved by conventional freezing method (45.2%). In the OPS method, the lambing rate in EFS40, EDFS30 or EDFS40 groups were similar to that (57.1%) of fresh embryos, or to that (46.0%) of embryos cryopreserved by conventional freezing method. The highest lambing rate (51.4%) of the group of OPS was obtained when the embryos were vitrified with EDFS30. In conclusion, either the two-step straw method in which embryos were pretreated in 10% EG for 5 min and then exposed to EFS40 for 2 min, or the OPS method in which embryos were pretreated in 10% EG + 10% DMSO for 30 s and then exposed to EDFS30 for 25 s was a simple and efficient method for the vitrification of Boer goat morulae and blastocysts.     

小鼠2-细胞胚胎细管法和OPS法玻璃化冷冻保存技术的研究

本试验在室温 (2 0℃和 2 5℃ )条件下 ,利用不同浓度的玻璃化溶液 (EFS和EDFS) ,对小鼠 2 细胞胚胎进行细管法和OPS法玻璃化冷冻保存。在 2 0℃室温条件下 ,用EFS4 0平衡 1min细管一步法冷冻 ,解冻后囊胚发育率仅为35 .0 % ,和新鲜 2 细胞体外培养的对照组 (6 5 .0 % )的差异极显著 (P <0 .0 1)。当 2 细胞胚胎在 10 %EG +10 %D溶液中预处理 5min ,再移入EDFS中平衡 30s二步法冷冻保存 ,解冻后囊胚发育率达 4 7.8%～ 4 8.8% ;当室温升至2 5℃时 ,二步法冷冻保存后 2 细胞的囊胚发育率达到 5 2 .2 % ,与对照组无显著差异 (P >0 .0 5 )。改用OPS二步法EFS30冷冻组保存后的 2 细胞胚胎的囊胚发育率高达 6 2 .2 % ,为试验中的最佳组。用最佳细管法和OPS法冷冻组解冻后培养至囊胚移植给受体母鼠均获得产仔     

Effect of cryoprotectant composition on in vitro viability of in vitro fertilized and cloned bovine embryos following vitrification and in-straw dilution

In this study the efficacy of the combination of glycerol (GLY) and ethylene glycol (EG) as cryoprotectants in a vitrification method developed for direct embryo transfer was evaluated by in vitro development of in vitro fertilized (IVF) and somatic cell nuclear transfer (SCNT) embryos after vitrification. The IVF and SCNT blastocysts were vitrified in either 40% GLY, 30% GLY + 10% EG, or 20% GLY + 20% EG using French straws. After warming, the straws were held vertically for 1 min without shaking and were then placed horizontally for 5 min to dilute the cryoprotectants. After washing, the vitrified-warmed embryos were cultured in vitro for 72 h. There were no differences among the vitrification solutions with respect to the rates of vitrified-warmed IVF and SCNT embryos surviving and developing to the hatched blastocyst stage. However, the rates of development to the hatched blastocyst stage of the SCNT embryos vitrified with 40% GLY tended to be higher than those vitrified with 30% GLY + 10% EG or 20% GLY + 20% EG (26% vs. 7-8%, respectively). The development rates to the hatched blastocyst stage of the IVF and SCNT embryos vitrified with solution containing EG were significantly lower (P<0.05) than those of non-vitrified embryos. These results suggest that use of the combination of GLY and EG as cryoprotectants had no beneficial effect on the viability of embryos after in-straw dilution. However, this method is so simple that it can be used for practical direct transfer of vitrified embryos in the field.     

牛体外受精胚胎一步脱防冻剂冷冻方法的研究

为了研究适合于牛体外受精胚胎的一步除防冻剂的冷冻方法，特进行两个试验。试验１分别用１．５Ｍ甘油＋０．２５Ｍ蔗糖、１．５Ｍ乙二醇和１．５Ｍ丙二醇作防冻剂冷冻体外受精后第７天，已发育至囊胚阶段的牛胚胎。使胚胎降温至－７℃后，植冰，然后以０．３℃／分的速率降温至－３０℃，立即将胚胎投入液氮中冷冻保存。在３７℃水中解冻胚胎后，使其直接在含１５％胎犊血清（ＦＣＳ）的磷酸缓冲液（ＰＢＳ）中脱去防冻剂。经体外培养７２ｈ后，３组胚胎的孵化率分别为７７．２７％（１０２／１３２）、７３．２４％（１０４／１４２）、４７．９０％（５７／１１９），第１、２组的孵化率极显著高于第３组（Ｐ＜０．０１），说明用１．５Ｍ丙二醇溶液冷冻的胚胎，在解冻后不宜直接在ＰＢＳ中脱防冻剂。试验２比较用不同浓度（１．０Ｍ０１．５Ｍ，２．０Ｍ）的乙二醇和不同投液氮温度（－２５℃，－３０℃，－３５℃）冷冻胚胎的效果。结果表明乙二醇浓度和投液氮温度对胚胎孵化率均无显著影响（Ｐ＞０．０５），各组胚胎的孵化率变动于７４．４４％－８５．４８％之间。     

绵羊玻璃化冷冻胚胎直接移植试验研究

应用EFS40玻璃化液对6.5～7日龄的绵羊胚胎进行玻璃化冷冻及解冻后直接移植试验.结果:桑椹胚、囊胚冷冻解冻后移植的妊娠率分别为37.50%(3/8)和54.55%(6/11),胚胎存活率分别为33.33%(3/9)和50.00%(6/12),差异均不显著(P＞0.05);胚胎解冻后用0.5 mol/L蔗糖脱防冻剂与直接用胚胎存放液脱除防冻剂的妊娠率分别为44.44%(4/9)和50.00%(5/10),胚胎存活率分别为40.00%(4/10)、45.45%(5/11)差异不显著(P＞0.05);10枚解冻后的胚胎细管内脱防冻剂后,直接装管移植给8只受体,妊娠率为50.00%(4/8),胚胎成活率为40.00%(4/10),与同期常规冷冻解冻组相比无显著差异(P＞0.05).     

Survival of mouse embryos after vitrification depending on the cooling rate of the cryoprotectant solution

The aim of the study was to determine the relationship between the rate of cooling of eight-cell mouse embryos to the temperature of liquid nitrogen (-196 degrees C) and their developmental capacity after thawing on the basis of their ability to leave the zona pellucida ('hatching') during in vitro culturing. Eight-cell embryos were obtained from superovulated female mice and divided into three experimental and one control group. Embryos from the experimental groups were cryopreserved by the vitrification method using ethylene glycol as cryoprotectant. The vitrification protocols used in the study differed in the rate of cooling of the cryoprotectant solution. Embryos from the first group were frozen in conventional 0.25-ml plastic straws, those from the second group in pipetting 'tips', and embryos from the third group, placed in vitrification solution, were introduced dropwise directly into liquid nitrogen. The control group of embryos was cultured in vitro without freezing in a culturing medium in an environment consisting of 95% air and 5% CO2. The developmental capacity of thawed embryos was assessed on the basis of their ability to leave the zona pellucida ('hatching') after three days of in vitro culturing. In the control group 95.1% of embryos 'hatched'. A significantly higher number of embryos that 'hatched' after thawing was observed in the group introduced dropwise directly into liquid nitrogen (60.0%) compared to the group frozen in pipetting 'tips' (37.9%). The group frozen in straws yielded significantly the lowest proportion of 'hatching' embryos (8.1%). These results showed that increasing cooling rates during vitrification of embryos improved their survival.     

A comparison of different vitrification devices and the effect of blastocoele collapse on the cryosurvival of in vitro produced porcine embryos

The aim of this study was to determine the optimum conditions for vitrifying in vitro produced day 7 porcine embryos using different vitrification devices and blastocoele collapse methods. Firstly embryos were collapsed by micro-pipetting, needle puncture and sucrose with and without conducting vitrification. In the next experiment, non-collapsed embryos were vitrified in an open device using either superfine open-pulled straws (SOPS) or the CryoLoop^TM system, or vitrified in a closed device using either the CryoTip^TM or Cryo Bio^TM’s high security vitrification system (HSV). The post-thaw survival of embryos vitrified in the open devices did not differ significantly (SOPS: 37.3%; CryoLoop^TM: 37.3%) nor did the post-thaw survival of embryos vitrified in the closed devices (CryoTip™: 38.5%; HSV: 42.5%). The re-expansion rate of embryos that were collapsed via micro-pipetting (76.0%) did not differ from those that were punctured (75.0%) or collapsed via sucrose (79.6%) when vitrification was not performed. However, embryos collapsed via sucrose solutions (24.5%) and needle puncture (16.0%) prior to vitrification were significantly less likely to survive vitrification than the control (non-collapsed) embryos (53.6%, P < 0.05). The findings show that both open and closed vitrification devices were equally effective for the vitrification of porcine blastocysts. Collapsing blastocysts prior to vitrification did not improve survival, which is inconsistent with the findings of studies in other species. This may be due to the extremely sensitive nature of porcine embryos, and/or the invasiveness of the collapsing procedures.