• Journal of Embryo Transfer
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• v.14 no.2
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• pp.99-106
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• 1999

핵 이식에 공여되는 수핵난자의 효과적인 동결보존을 위하여 한우 성숙난자를 1.0 M dimethylsulfoxide(DMSO) 또는 1.0 M glycerol이 함유된 동결보호제를 이용하여 처리하거나, 동결보호제 처리 후 완만동결법을 이용한 동결융핼르 시행하여 상기 실험처리로 야기되는 투명대 경화현상을 관찰하였다. 도축장 유래의 난소에서 미성숙난자를 채취한 후 10% 소 태아혈청을 함유한 TCM-199을 이용하여 22∼24 시간 동안 체외성숙배양을 이해하였다. 배양후 작출된 성숙난자를 각각의 동결보호제로 처리, 혹은 처리 후 동격융해한 후 protease를 이용하여 투명 대의 경화현상 발생의 빈도를 조사하였다. 또한 동격란을 동결정액을 이용한 체외수정에 공여한 후 정자 침입농도능을 조사하였다. 동결보호제로 처리한 난자에 있어서 보호제의 종류와 관계없이 투명대 경화현상이 유의적 (P<0.05) 으로 증가하였으나 이후의 동결융해 처리에 의한 추가적인 경화현상의 발생은 증가하지는 않았다. 또한 투명대 경화현상의 발생양상을 동결보호제 처리 후 10분 간격으로 측정한 결과 DMSO의 경우 처리후 10분, glycerol의 경우 처리 후 20분 후부터 유의적으로 차를 발견할 수 없었으며, 수정율 및 난자 1개당 침입한 정자의 수는 동결란에서 유의적으로 증가하지 않았다. 본 연구의 결과 동결난자의 투명대 경화현상은 동결보호제 처리과정에서 이미 일어나지만, 이러한 투명대 경화현상이 난자의 동결보존 후 수정능에는 현자한 영향을 미치지 않는다는 사실이 규명되었다.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.81-81
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• 2003

돼지 정액의 동결보존은 돼지 정자가 내동성이 약한 특성을 가지고 있어 아직 만족할만한 결과를 얻지 못하여 액상정액을 이용하여 인공수정을 실시하고 있는 실정이다. 돼지 정액의 동결보존을 효과적으로 이룩한다면 돼지 인공수정의 효율성을 증대시킬 수 있고, 우수한 종돈의 보호 및 국제적 돼지 품종의 교류를 증진시킬 수 있을 것이다. 본 실험은 돼지 정액 동결시 동결온도와 시간, 항산화제로 알려진 Taurine의 농도별 첨가, 동해보호제 및 융해조건이 돼지 정액의 동결 융해후 생존성에 미치는 영향을 검토하고자 수행되었다.

• Korean Journal of Plant Resources
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• v.17 no.2
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• pp.75-81
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• 2004

This study was conducted to investigate effects of cryopreservation by vitrification on the seed germination rate and growth and physiological properties of seedlings of Maackia amurensis. Cryopreservation significantly decreased the germination rate of seeds of M. amurensis, but the reduction of germination rate was mitigated by the treatment of cryoprotectant (plant vitrification solution, PVS2) before plugging into liquid nitrogen and fast thawing rate after cryopreservation. Long-term PVS2 exposure decreased seed germination rate, whereas cryopreservation time didn't have influence on seed germination rate. In addition, growth and physiological properties of seedlings were not affected by PVS2 exposing time and cryopreservation time. Therefore cryopreservation could be widely used as a technique of long-term ex situ conservation without any damage and deterioration of cells or tissues of the forest seeds. However, in order to increase the effect of cryopreservation, we have to develope the lower toxic cryoprotectant and suitable techniques to the structural or chemical properties of a variety of seeds.

• 대한생식의학회:학술대회논문집
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• 2005.06a
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• pp.107.2-108
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• 2005

• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.224-227
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• 2022

In this study, the protective effects of turanose on Saccharomyces cerevisiae (Baker's yeast) were examined during the freeze-drying process to evaluate the feasibility of utilizing turanose as a novel cryoprotectant. The survival rate of the Baker's yeast cells improved substantially with a cryoprotective medium containing turanose in a substitution-dependent manner. In accordance with these survival rates, the yeast cell surfaces became smoother as the turanose content increased. Turanose with skim milk maintained the viability of the Baker's yeast, which improved substantially upon storage at -20℃. Thus, it is thought that turanose will exhibit excellent preservation effects during the distribution of Baker's yeast. Finally, these results suggest that turanose has the potential to be used as a novel cryoprotectant against various microorganisms.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.163-169
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• 2013

Cryopreservation of poultry semen has been reported, but preservation of female genetic material has not been possible because of the unique anatomical and physiological characteristics of the avian egg. Thus an alternative strategy for conservation of oviparous species of animals must be developed. Recent technological developments for producing germline chimeras by the transfer of primordial germ cells (PGCs) into recipient embryos has enabled the conservation and retrieval of chicken genetic resources in their complete form. In the present study, fertilized eggs were incubated for about 5.5 days to obtain embryos at stage 28. The whole embryo was collected from the germinal gonad using a fine glass micro pipette under a microscope. The PGCs were then purified using MACS method. Two commercially available cryoprotectants (A and B) were used to preserve the PGCs, and EG were used as a control. The average recovery rate of PGCs after thawing was 35.5% and 60.5% with the A and B treatments, respectively. There was no significant difference between B treatments and control, which showed an average recovery rate of 52.8%. However, the recovery rate obtained using A cryoprotectant (35.5%) was significantly lower than using treatment control and B. The average viability of the PGCs after thawing were 77.9% and 77.4% for cryoprotectants A and B, respectively, and the control were was 81.6%. There was no statistically significant difference between the two treatments and control. It was concluded that all of the available cryoprotectants examined in this study could be used for preservation of PGCs from embryos. Further experiments to produce germline chimera from PGCs preserved using this techniques are strongly recommended.

• Microbiology and Biotechnology Letters
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• v.43 no.4
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• pp.385-390
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• 2015

In order to develop an eco-friendly biofertilizer, a plant growth promoting rhizobacterium (PGPR), Bacillus sp., SH1RP8 was investigated. SH1RP8 was lyophilized via freeze-drying along with other protective agents that protect cells from lysis. The freezedried powder of Bacillus sp. SH1RP8, containing 5% skim milk (w/v), exhibited the highest survival rate of 30.6% among all the protective agents (skim milk, glucose, and peptone). The lyoprotective effect of the skim milk, mixture including 5% skim milk, and substrates on the survival of the test strain was examined. Control group was added only skim milk and test groups were added skim milk and other substrates. As a result, the group supplemented with both glycerol and 5% skim milk showed the protective effect much higher by 214.29% than the control group. Freeze-dried Bacillus sp. SH1RP8 could be a good candidate as a potential biofertilizer due to its effective PGPR activity.

• Korean Journal of Animal Reproduction
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• v.23 no.1
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• pp.75-84
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• 1999

This study assessed development in vitro of pronuclear(PN) stage embryos cryopreserved by the method of either vitrification or slow freezing, by using of different cryoprotectants, and equilibration and cooling rate, in rabbit. Ethyleneglycol- ficoll- sucrose(EFS) or ethyleneglycol- polyvinylpyrrolidone - galactose- (EPG-I) for vitrification, and EPG- II for slow freezing as cryoprotectant were used. The pronuclear embryos were exposed to EFS for 0 to 5 min and diluted with D-PBS and/or pre-dilution with 0.5 M sucrose. To examine the viability of frozen-thawed embryos, PN embryos were co-cultured with bovine oviductal epitherial cell(BOEC) for 5 days to hatching blastocyst stage in 39 $^{\circ}C$ 5% $CO_2$incubator. The results obtained were as follows: The dilution with 0.5 M sucrose and D-PBS after the exposure to EFS for 1.0 min resulted in no significant(P＜0.05) decrease in the development of PN embryos to hatching blastocyst(72.0%), compared with controls. The development of PN embryos cryopreserved to hatching blastocyst was not significantly (P＜0.05) different between EFS for 1.0 min(72.0%), EPG-I for 1.0 min(72.0%) and EPG-II for 30 min(66. 7%). The post-thaw development of PN embryos to hatching blastocyst was similarly very low as 6.1% and 11.5% in vitrification with EFS and slow freezing with EPG-II, respectively. The incidence of post-thaw zona-crack in PN embryos cryopreserved by slow freezing with plunging to liquid nitrogen at －35$^{\circ}C$ was signicantly(P＜0.05) higher(25.0%), compared with －85$^{\circ}C$ (1.9%). These results indicated that the rabbit PN embryos could be cryopreserved with either vitrification or slow freezing procedure, and frozen PN embryos could be successfully developed in vitro to haching blastocyst. but the post-thaw development of cryopreserved PN embryos was still very low under the present conditions.

• Development and Reproduction
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• v.15 no.4
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• pp.281-289
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• 2011

The objective of this study was to investigate the effective cryoprotectants for the cryopreservation of porcine mesenechymal stem cells (pMSCs). In order to understand the effectiveness of various cryoprotectants on pMSCs, we studied the most commonly used cryoprotectants; dimethyl sulfoxide (DMSO), ethylene glycol (EG), DMSO and EG. pMSCs were isolated from bone marrow matrix of piglet (2 month) and characterized by alkaline phopshatase (AP) activity, colony forming, and differentiation to adipocyte. In slow cooling cryopreservation, the pMSCs were exposed to cell medium containing Dulbecco's Modified Eagle's Medium (DMEM) supplemented with 10% DMSO, 1.5M EG and 5% DMSO/0.75M EG, respectively, and freezed to $-1^{\circ}C$/min from $25^{\circ}C$ up to $-80^{\circ}C$ in a cryo-container. The proportion of viable cells and the growing rates in fresh pMSCs were significantly (P<0.05) higher than those of other groups, but did not differ between the cryopreserved groups. The expression of Sox-2 and Nanog gene was increased by extending culture time in cryopreserved groups. The expression of Bax gene in cryopreserved groups was similar with fresh pMSCs. Moreover, the gene expression of adipocyte-specific marker as well as chondrogenic/osteogenic factors in cryopreserved groups was similarly to fresh pMSCs. Taken together, our results suggested that all these cryoprotectants of 10% DMSO, 1.5M EG and 5% DMSO/0.75M EG could be used for cryopreservation of the pMSCs.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.655-659
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• 2014

Food-grade protective agents, namely, skim milk, yeast extract, soy powder, and trehalose, were studied for their ability to improve the viability of freeze-dried lactic acid bacteria (LAB), including Weissella cibaria SW1-1, Lactobacillus plantarum A-1, Lactobacillus sakei 2-12 24, and Leuconostoc citreum 3526. The best results were obtained with 10% soy powder; approximately 90% cell viability was observed during the freeze-drying process. Increase in the concentration of soy powder did not cause a proportional increase in the survival rate of LAB. Further, no significant difference was observed when two agents were combined in a 1:1 ratio (p<0.05).