본 실험은 국화의 바이로이드 제거에 이용되는 초저온처리 시 국화 품종 'White ND'을 적합한 처리조건을 확립하기 위해 초저온처리의 단계별 요인을 실험하였다. 그 결과 생장점의 크기는 1 mm(엽원기 2~3매 포함)에서 높은 생존율과 신초 재생율을 나타내었고, vitirification 처리시 PVS3가 효과적이었으며, 처리 시간은 60분 처리 하였을 때 높은 생존율 및 정 상 신초 재생율을 보였다. 또한 vitrification을 위한 전처리 조건은 sucrose 농도를 88 mM 24시간, sucrose 0.3 M 16시간, sucrose 0.5 M 6시간, sucrose 0.7 M 3시간으로 처리하는 것이 초저온 처리 후 생존율 및 신초 재생율을 높이는데 효과적이었으며, 재생된 정상 식물체는 모본과 비교하여 ploidy level이 동일한 것으로 보아 식물체의 유전적 변이가 일어나지 않았다.

This study was carried out to study the survival rate of thawed Hanwoo embryos frozen by the slow-rate freezing or the cryotop vitrification method. Hanwoo cumulus-oocyte complexes were recovered from ovaries at a slaughter house, matured for 20~22 hours, fertilized with Hanwoo semen for 5~6 hours, and cultured for 7~9 days in 38.5℃, 5% CO2 incubator. For freezing, Day 7∼9 blastocysts were collected. Embryos for the slow-rate freezing were equilibrated in 1.8 M ethylene glycol (EG) with Dulbecco's phosphate-buffered saline (D-PBS). Programmable cell freezer was precooled down to —7℃, and the straw was seeded during 8 minutes-holding time, and was cooled to —35℃ at the cooling rate of 0.3℃/min, and then was plunged and stored in liquid nitrogen. Embryos for the cryotop vitrification were treated in TCM199 with 0.5 M sucrose, 16% EG, 16% dimethylsulfoxide (DMSO). Embryos were then loaded individually onto cryotop and plunged directly into liquid nitrogen. The survival rates of embryos frozen by these two freezing methods were evaluated at 12 to 24h post-thawing. The survival rates of frozen/thawed Hanwoo embryos by the cryotop vitrification method (56.86 ± 26.53%) were slightly higher than those by the slow-rate freezing method (55.07 ± 26.43%) with no significant difference. Using the cryotop vitrification and the slow-rate freezing of Hanwoo blastocysts on Day 7 following in-vitro fertilization (IVF) treatment, the survival rates of frozen/thawed Hanwoo embryos were 72.65 ± 18.3% and 79.06 ± 17.8%, respectively. The survival rates by the cryotop vitrification were higher than those by the slow-rate freezing on both Day 8 and 9 with significantly higher survival rate on Day 9 (p<0.05). Using the cryotop vitrification and the slow-rate freezing of Hanwoo embryos to compare between three different blastocyst stages, the survival rates of the blastocyst stage embryos were 66.22 ± 18.8% and 45.76 ± 12.8%, respectively with higher survival rate by the vitrification method (p<0.05). And the survival rate of expanded blastocysts was higher than those of early blastocysts and blastocysts in two freezing methods with significantly higher survival rate by the slow-rate freezing method (p<0.05).

The objective of this study was to investigate the effectiveness of cryopreservation methods for the effect of various vitrification containers, such as EM-grid, OPS, or cryo-loop on the survival and developmental rate of vitrified mouse pronuclear embryos, and mouse cleavage embryo, at 21, 24, 27 and 30 hr after hCG injection. Post-thaw cleavage was similar among treatments, while the developmental rates of mouse blastocyst and hatched blastocyst were higher ( <0.05) in 27 hr and 30 hr than 21 hr. The developmental rate of hatched blastocyst at vitrified cleavage mouse embryos in cryo-loop was significantly higher than vitrified pronuclear embryos of control group as well as EM-grid and OPS ( <0.05). The developmental rate using cryo-loop was higher than EM-grid, but in case of OPS at vitrified cleavage and mouse pronuclear embryos, no significant difference was noticed. These results of our study show that the developmental rates of mouse embryos were unaffected by various vitrification containers, but in case of mouse embryos and hatched blastocysts at late vitrified pronuclear embryos the developmental rates were higher than early vitrified pronuclear embryos. Moreover, the developmental rate of hatched blastocyst at vitrified cleavage mouse embryos was significantly higher than vitrified pronuclear embryos. For better execution of this study, it will be mandatory to include improvement of vitrification containers, cryopreservation methods and conditions, higher survival rate, safe preservation, contamination and embryo loss.

The present study was performed to investigate the survival and subsequent embryonic developmental rate of immature and mature oocytes after vitrification and pronuclear stage embryos after slow-freezing and vitrification. We have also tried to examine the dependency of concentrations (7.5, 15%) and exposure time (5, 10, 20 min) of ED cryoprotectant on developmental rate of pronuclear stage embryos. The developmental rates of 2-ce1l and blastocyst embryos at mature oocytes were significantly (p<0.05) higher than immature oocytes. After slow freezing, vitrification and thawing of pronuclear stage embryo, the survival and developmental rates of blastocysts and hatched blastocysts were significantly (p<0.05) higher after vitrification than after slow-freezing. On contrary, the developmental rates of 2-cell embryos were significantly (p<0.05) higher after slow freezing than after vitrification. The cryopreservation methods of pronuclear stage embryos vitrified by exposed to 7.5% ED solution for 5 minutes was significantly (p<0.05) higher than other experimental group. The results of our study suggest 1hat the developmental rates of mature oocytes have been more successful than immature oocytes during vitrification. Vitrification was more efficient than slow freezing in case of pronuclear stage embryos. The effective cryopreservation method of pronuclear stage embryos was vitrified by exposed to 7.5% ED solution for 5 minutes.

The purpose of this study was to compare the efficiency of slow freezing with that of vitrification method for the cryopreservation of human embryos. Human embryos were derived from in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) and the mixed solution of propanedial (1.5, 1.0, 0.5M PROH) and sucrose (0.1M), ethylene glycol (7.5, 15%), dimethyl sulfoxide (7.5, 15% DMSO), sucrose (0.5, 1.0M) and SPS (Serum Protein Substitute) was used for a cryoprotectant for slow freezing and vitrification solution, respectively. Rates of recovery after thawing, morphological normality, post-thaw viability, arrest, morphological abnormality and preimplantation development were compared between two protocols. After freezing-thawing, recovery and survial rate of slow freezing was (88.6% and 73.4%), whereas vitrification was (99.2% and 96.2%) (p<0.05). The arrest rate of slow freezing was significantly lower compared with those of vitrification(8.7% vs 29.9%) (p<0.05). Preimplantation development to the 2-cell (83.8% vs 67.7%), 4-cell (69.0% vs 47.2%) and 8-cell (62.4% vs 37.8%) stages 24, 48 and 72 h after thawing, respectively, were higher in the slow freezing than the vitrification. After slow freezing and vitrification of human embryo at 2-8cell stage, the rate of recovery rate, survival rate and partial damage rate were 92.0% vs 100%, 80.4% vs 96.2% and 52.2% vs 19.0%, respectively. And partial damage rate was significantly lower than those of slow freezing method (p<0.05). These results demonstrate that a slow freezing using PROH is more efficient than a vitrification for cryopreserving the human zygotes, although the vitrification yielded better recovery, survival and partial damage of frozen-thawed 2-8 cell stage embryos than slow freezing method.

본 연구는 마우스의 성숙 난자와 수정란의 유리화 동결을 위한 CPS, 기존 straw 및 OPS 방법의 효과에 대하여 비교하였다. 마우스 난자의 유리화 동결-응해 후 형태학적인 생존율을 조사한 결과, CPS (75%)와 기존 straw(72%)법이 OPS(68%)법에 비해 유의적으로 높은 생존율을 나타내었다(p<0.05). 과배란 처리 후 채란한 2-세포기 마우스 수정란을 유리화 동결-응해하여 일간 배양한 다음 수정란의 배 발달 상태를 비교한 결과, 동

본 연구는 돼지 미성숙 난포란의 유리화 동결액에 노출시 독성과 삼투압 스트레스가 가장 적은 유리화 동결액을 조사하기 위하여 실시하였으며, 그 결과를 요약하면 다음과 같다. 미성숙 난포란을 EFS(40% ethylene glycol +18% ficoll +0.3 M sucrose) 용액, ES(5.5 M ethylene glycol +1.0 M sucrose) 용액, GE(10% glycerol +20% ethylene glycol) 용액에 각각 노출하고 대조구로 아무 처리하지 않은 난포란을 체외성숙하여 관찰한 체외성숙율은 ES 용액과 대조구 에서 EFS 용액과 GE 용액보다 유의적으로 높았으며(P<0.05), 유리화 동결액의 독성에 의한 난포란의 퇴화율은 대조구, ES 용액, EFS 용액, GE 용액 순으로 유의적으로 낮은 퇴화율을 나타내었다(P<0.05). 미성숙 난포란을 EFS 용액, ES용액, GE용액에 각각 노출하고 대조구로 아무 처리하지 않은 난포란을 체외성숙, 체외수정하여 관찰한 정상 수정율은 대조구가 세 종류의 유리화 동결액보다 유의적으로 높았고(P<0.05), 유리화 동결액 간에는 유의적인 차이가 없었다. 다정자 침입율과 난자당 침입한 평균 정자수는 모든 처리구간에 유의적인 차이가 없었다. 미성숙 난포란을 EFS 용액, ES 용액, GE 용액에 각각 노출하고 대조구로 아무 처리하지 않은 난포란을 체외성숙, 체외수정, 체외 배양하여 관찰한 수정 3 일째의 분할율은 ES 용액과 대조구가 EFS 용액과 GE 용액보다 유의적으로 높았으며(P<0.05), 수정 7일째의 배반포 형성율은 모든 처리구간에 유의적인 차이가 없었다. 배양기간 동안 나타난 퇴화율은 대조구가 세 가지 유리화 동결액에 비해 유의적으로 낮았고(P<0.05), ES 용액은 EFS 용액과 GE 용액보다 유의적으로 낮은 퇴화율을 나타내었다(P<0.05).

본 연구는 돼지 배아의 유리화 동결 시 CB 처리군과 CB 비처리군의 영향을 비교하였다. CB의 농도별, 처리 시간별로 처리한 뒤 유리화 동결 융해 후 정상적인 형태 회수율과 생존률을 각각 조사하였다. 1. CB를 전 처리한 군과 비처리군의 정상적인 형태율이 각각 84.2%, 81.9%로 유의한 차이가 없었으나, 융해 후 72시간 째 생존률의 결과에서는 각각 60.5%, 32.8%로 유의성(p<0.1)이 검증되었다. 2. CB 농도별 생존률에 미치는 영

This study evaluated the efficiency and compared with different materials of loading vessels for vitrification-plastic/glass, copper grid and nylon. The loading method, vitrification, cryop-reservation and warming method of the oocytes were examined. The loading samples prepared in manual or company-made and sterilized, loaded the COCs selected on each samples and cultured for maturation during 40 hours, and then exposed sequentially to ethylene glycol solution. Thawing method was reversely treated and exposed for warmed oocytes. After oocytes were thawed, fertilized and cultured in vitro for 3-4 hours, rates of development and morphological appearance were examined. The results were as summarized: ㆍOPS from company-made or hand-made of the hematocrit micropipettes, NLS from fishing line and EMG from company-made for EM were used for loading oocytes, respectively. ㆍThe efficiency of freezing method and loading convenience were orderly higher in OPS, NLS and EMG. The optimal capacity per vessel was orderly lowered in NLS, EMG and OPS, respectively. ㆍAfter oocytes were warmed, the recovery rate, morphology and rate of development were orderly higher in OPS, NLS and EMG, respectively. ㆍIn conclusion, OPS has the advantages of achieving a little more survival and preserving results than other two loading methods.

Human embryonic stem (hES) cell lines have been derived from human blastocysts and are expected to have far-reaching applications in regenerative medicine. The objective of this study is to improve freezing method with less cryo-injuries and best survival rates in hES cells by comparing various vitrification conditions. For the vitrifications, ES cells are exposed to the 4 different cryoprotectants, ethylene glycol (EG), 1,2-propanediol (PROH), EG with dime-thylsulfoxide (DMSO) and EG with PROH. We compared to types of vehicles, such as open pulled straw (OPS) or electron microscopic cooper grids (EM grids). Thawed hES cells were dipped into sequentially holding media with 0.2 M sucrose for 1 min, 0.1 M sucrose for 5 min and holding media for 5 min twice and plated onto a fresh feeder layer. Survival rates of vitrified hES cells were assessed by counting of undifferentiated colonies. It shows high survival rates of hES cells frozen with EG and DMSO (60.8％), or EG and PROH(65.8％) on EM grids better than those of OPS, compared to those frozen with EG alone (2.4％) or PROH alone (0％) alone. The hES cells vitrified with EM grid showed relatively constant colony forming efficiency and survival rates, compared to those of unverified hES cells. The vitrified hES cells retained the normal morphology, alkaline phosphates activity, and the expression of SSEA-3 and 4. Through RT-PCR analysis showed Oct-4 gene expression was down-regulated and embryonic germ layer markers were up-regulated in the vitrified hES cells during spontaneous differentiation. These results show that vitrification method by using EM grid supplemented with EG and PROH in hES cells may be most efficient at present to minimize cyto-toxicity and cellular damage derived by ice crystal formation and furthermore may be employed for clinical application.

본 연구는 미성숙, 성숙 단계의 돼지 난포란이 유리화 동결에 의한 동결보존이 가능한지를 조사 하고자 실시하였다. 난포란은 세포질 내 지방구를 분극시키기 위해 원심분리를 실시하였고, 미세조작기를 이용하여 지방구를 제거하였다. 돼지 난포란을 CB 처리하여 원심분리 후 지방구를 제거한 지방제거구(Delipated), CB 처리 후 원심분리만 하여 지방구를 분극시킨 원심분리구(Centrifuged), 아무처리도 하지 않은 대조구(Control)를 EM grid

This study was performed to evaluate whether vitrification method using ethyle glycol and eletron microscopic (EM) grid could be used far the cryopreservation of human oocytes in ART program. Surplus oocytes were obtained from consented IVF patients. These surplus human oocytes were frozen with our vitrification method, Oocytes were exposed to 1.5M ethylene glycol (EG) in DPBS far 2,5 minutes, followed by 5.5M EG plus 1.0M Sucrose in DPBS for 20 seconds. Then oocytes were transferred onto the EM grid and the grid was plunged into LN2 for storage. For thawing, oocytes containing EM grid were sequentially transferred in 1.0M, 0.5M, 0.25M, 0.125M and 0 M sucrose in DPBS solution at the intervals of 2.5 minutes. Thawed and survived oocytes were provided for ICSI. Embryos from vitrified oocytes were transferred to uterus of the patient on 4 to 5 days after ovulation in natural cycles of on 15 to 17 day of hormone replacement cycles. A total of 370 oocytes from 26 patients were thawed and 159 (43.0%) of them survived. One hundred thirty four oocytes (84.3%) were fertilized normally and 126 pre-embryos were transferred to 26 patients, resulting in 5 clinical pregnancies. The pregnancy rate per transfer was 19.2% and implantation rate was 4.0%. Among the five pregnant, 4 patients delivered 4 healthy babies and the one patient was 32-week ongoing pregnancy. From this results, vitrification using ethylene glycol as cryoprotectant and EM grid is a rapid and simple method that can be effectively applied for the cryopreservation of human oocytes in ART program.

Selection of oocyte cryopreservation method is a prerequisite factor for developing an effective bank system. Compared with slow freezing method, the vitrification has various advantages such as avoiding intracellular ice crustal formation. In our previous, we attempted to employ a vitrification method using ethylene glycol and an electron microscope grid for cryopreservation of mouse oocytes. However, A high incidence of spindle and chromosome abnormalities was detected in thawed oocytes after vitrification. We examined whether the addition of a cystoskeleton stabilizer Taxol , to the vitrification solution could promote the post-thawed survival and subsequent development of stored oocytes. More oocytes developed to the 4-cell (44.7% vs. 69.7%), 8-cell (31.8% vs. 64.2%), morula (24.7% vs. 54.3%), and blastocyst (20.3% vs. 49.2%) stages after the addition of Taxol to the cryoprotectant than after no addition. 21 and 26 mouse pups were born after transfer of blastocyst derived from oocytes vitrified without and with Taxol. The addition of Taxol to vitrification solution greatly promoted post-thaw preimplantation development of ICR morose oocytes.tes.

To develop an effective vitrification method, we examined the use of a conventional straw as vessel fur vitrification of mouse oocytes, and to compare the post-thaw survival and chromosome configuration of these oocytes with those vitrified in grids. Intact cumulus-enclosed oocytes were vitrified with DPBS with 5.5 M ethylene glycol and 1.0 M sucrose, and loaded into straws and onto eletron microscopic copper grid fur storing in liquid nitrogen. Intact vitrified and thawed oocytes were karyotying for chromosome. The rates of post-thawed survival were 88.5% in vitrified oocytes with straws, and 83% in vitrified ooctyes with grids. Vitrified and thawed oocytes with straws and grids were increased chromosomal abnormality (31.4% and 30.9%) compared with fresh oocytes (17.8%). The conventional straws can be used as vessel for vitrification to prevent of inflection in liquid nitrogen.