• KSBB Journal
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• v.21 no.4
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• pp.306-311
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• 2006

Cell preservation is indispensable in animal cell culture process and should be established according to the cell characteristics. In this study, we experimented hypothermic preservation of CHO cells that is widely used in pharmaceutical industry to produce therapeutic proteins and established a stable method of preservation. The highest viability of CHO cells was obtained when the cells were preserved using rolling tube, which means the cells should be suspended to avoid the cell lumping during the preservation. Also, we obtained superior preservation result under the anaerobic condition. To evaluate the serum-free media as a preservation solution, we investigated cell growth after hypothermic preservation using serum-free media. High cell viability and normal cell growth was observed during 10 days using serum-free media. Moreover, we found that more effective preservation when ${\alpha}$-tocopherol and retinoic acid is added to media as an additive. In the case of 1 liter large scale hypothermic preservation using established protocol, cell viability and growth rate was obtained as good as small scale one. This study is considered to be helpful for hypothermic preservation of CHO cells and large scale hypothermic preservation may be available through the further studies.

• KSBB Journal
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• v.24 no.3
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• pp.312-320
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• 2009

Stable cell preservation is an essential factor in the regenerative medicine for cell therapies and transplantation of biologic materials. In this study, we studied to provide more stable hypothermic preservation by protection of cell damage during the preservation at $4^{\circ}C$. The result of searching for key components that have excellent efficacy in hypothermic preservation of cells, we have identified the fact that the hypothermic preservation adding protein hydrolysates such as yeast hydrolysate is far superior to others. All protein hydrolysates that are derived from animal, plant and microbe sources have superior efficacy, especially the peptides which have molecular weights under 10 kDa have the best efficacy among the components of protein hydrolysate. The protein hydrolysates prevented the decrease of ATP level in the cells caused by hypothermic environment and they inhibited the generation of ROS. Adding antioxidants and control agents of osmotic pressure were showed to have more superior efficacy in hypothermic preservation. Finally, KUL261 solution (DMEM/F12 1 : 1 medium, yeastolate 1%, $\alpha$-tocopherol $100{\mu}M$, dextran 2.5%), the preservation solution developed in this study, showed the best efficacy in both cell viability and cell growth more than other conventional preservation solutions. In conclusion, the improved hypothermic preservation solution that contains the protein hydrolysates as a key component provide the best preservation efficacy. It provides better efficacy than other preservation solutions and will contribute to both the development of regenerative medicine and global commercialization in this therapeutic field.

• Journal of Veterinary Clinics
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• v.26 no.5
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• pp.445-449
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• 2009

For human organ transplantations, histidine-tryptophan-ketoglutarate solution (HTKS) and University of Wisconsin solution (UWS) have been shown to engender similar outcomes as gold standard cold preservation solutions ($4^{\circ}C$). To select the effective preservation solution for cold storage of kidney xenografts in miniature pig, which could be a potential source animal of bio-organs, this study compared early histopathological outcomes of cold preservation injury using HTKS and UWS. Twelve miniature pigs weighing 25.6 to 34.7 kg were divided into two groups (n = 6 per group), UWS group and HTKS group. The kidneys in each group were harvested, cold flushed, and preserved for 0, 24, 48, and 72 hrs at $4^{\circ}C$ with UWS or HTKS, respectively. Histolopathological examinations were assessed on kidney biopsy specimens, taken after each cold storage. The degree of renal injury was scored using 5 different criteria (pyknotic nuclei, disruption of cytoplasm, detachment of epithelium, loss of microvilli, tubular necrosis and loss of glomerular tufts) of the cellular components of the tissue. The degree of kidney damage was increased with prolonged cold ischemia time. UWS and HTKS have at least similar efficacy in kidney preservation within 24 hrs cold preservation time. However, in HTKS group cold-induced injury started to be observed more than in UWS group after 48 hrs of cold storage. In conclusion, UWS and HTKS were equally effective for cold preservation of miniature pig kidney in early preservation times; however, UWS may be more effective at longer preservation times as compared to HTKS.

• The Korean Journal of Mycology
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• v.34 no.2
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• pp.88-91
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• 2006

Attempts were made to investigate the conditions of mycelia of one low-temperature type strain and one high-temperature type strain of shiitake showing poor fruit-body formation in bed-log, and to survey harmful microorganisms formed on the log surface in Gapyung County, Korea. When tested the growing ability of mycelia, the low-temperature type strain showed ca. 1.1% decrease compared with preserved original strain. And, the high-temperature type one showed ca. 8.0% decrease. The growth of isolated mycelia was tested in sawdust medium. The high-temperature type strain showed ca. 10.8% decrease compared with original strain, and the low-temperature type one showed ca. 25.1% decrease. Weight reduction rate was investigated. The high-temperature strain showed ca. 20.1% decrease and the low-temperature one ca. 19.0%. When compared with non-treatment, original high-temperature type strain showed 107.0% decrease, the isolated high-temperature type strain 49.5%, original low-temperature type one 85.4%, isolated low-temperature type one 50.0%. As the results of confrontation culture, the high-temperature type strain and the low-temperature type one were same as the original ones, respectively. And, in the bed-logs, Hypoxylon truncatum, Coriolus versicolor, Inonotus xeranticus, Daedaleopsis tricolor, Graphostroma platystoma, two species of Myxomycetes, Trichoderma sp. Hypoxylon fragiforme, H. howeianum, and Nitschkia confertula were observed as harmful microorganisms, and the bed-logs were not in good condition.

• Restorative Dentistry and Endodontics
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• v.35 no.4
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• pp.285-294
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• 2010

The purpose of this study was to evaluate the viability of periodontal ligament cells of rat teeth after low-temperature preservation under high pressure by means of MTT assay, WST-1 assay. 12 teeth of Sprague-Dawley white female rats of 4 week-old were used for each group. Both side of the first and second maxillary molars were extracted as atraumatically as possible under tiletamine anesthesia. The experimental groups were group 1 (Immediate extraction), group 2 (Slow freezing under pressure of 3 MPa), group 3 (Slow freezing under pressure of 2 MPa), group 4 (Slow freezing under no additional pressure), group 5 (Rapid freezing in liquid nitrogen under pressure of 2 MPa), group 6 (Rapid freezing in liquid nitrogen under no additional pressure), group 7 (low-temperature preservation at $0^{\circ}C$ under pressure of 2 MPa), group 8 (low-temperature preservation at $0^{\circ}C$ under no additional pressure), group 9 (low-temperature preservation at $-5^{\circ}C$ under pressure of 90 MPa). F-medium and 10% DMSO were used as preservation medium and cryo-protectant. For cryo-preservation groups, thawing was performed in $37^{\circ}C$ water bath, then MTT assay, WST-1 assay were processed. One way ANOVA and Tukey HSD method were performed at the 95% level of confidence. The values of optical density obtained by MTT assay and WST-1 were divided by the values of eosin staining for tissue volume standardization. In both MTT and WST-1 assay, group 7 ($0^{\circ}C$/2 MPa) showed higher viability of periodontal ligament cells than other group (2-6, 8) and this was statistically significant (p < 0.05), but showed lower viability than group 1, immediate extraction group (no statistical significance). By the results of this study, low-temperature preservation at $0^{\circ}C$ under pressure of 2 MPa suggest the possibility for long term preservation of teeth.

• Food Industry And Nutrition
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• v.1 no.1
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• pp.71-80
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• 1996

김치의 보존성을 높여 가식기간을 연장시키고져 하는 연구는 김치의 숙성원리 측면에서 접근하는 것이 바람직하며, 이러한 접근에 있어서도 저온관리는 가장 기본적인 요소이다. 현재까지 이루어진 연구들은 주로 김치의 미생물 생육을 제어함으로서 보존성을 증진코져하는 시도가 많았다. 김치의 숙성에 영향을 줄 수 있는 요소들은 매우 다양하고 복잡함에도 일부 측면에 한정하여 보존성을 다룸으로서 지금까지 얻어진 효과가 미흡하지 않았나 판단된다. 김치 보존성을 증진시키기 위하여 중점을 두어야 할 몇가지 항목들은 (1)재료의 청정화 (2)소금절임에 대한 과학화 (3)효소저해제 개발 (4)호모형 젖산균의 선택적 저해 (5)완충제 및 중화제의 개발 (6)신맛의 완화 및 억제 물질 개발 (7)철저한 저온관리 등이다. 따라서 김치의 보존성에 영향을 줄 수 있는 다양한 측면에서 그리고 이들을 종합적으로 활용함으로서 보존성문제에 대한 해결이 가능할 것으로 판단된다.

• Korean journal of food and cookery science
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• v.15 no.5
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• pp.539-544
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• 1999

This study attempted to determine the effect of storage temperature(5$^{\circ}C$ and 25$^{\circ}C$) and time(1, 24, 48 and 72 hours) on the sensory and textural properties of mungbean starch gels. The color value, syneresis, texture and sensory properties of mungbean starch gels were measured. As the storage time increased, the lightness(L) and whiteness(W) values of mungbean starch gel increased. This trend was more apparent at the storage temperature of 5$^{\circ}C$. The syneresis of gels also increased as the storage time increased and the storage temperature was lower. As the storage time increased, the hardness of the gel increased whereas the adhesiveness and cohesiveness of the gel decreased. These results showed that mungbean starch gel lost its typical viscoelasticity during storage. This trend was also more apparent at the storage temperature of 5$^{\circ}C$. Sensory characteristics of the gel were well correlated with the mechanical characteristics. Overall quality of the gel decreased markedly at the 2nd day storage at 5$^{\circ}C$ and at the 3rd day storage at 25$^{\circ}C$.

• Korean Journal of Agricultural Science
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• v.1 no.1
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• pp.41-46
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• 1974

Fertilized rabbit ova at 16-cell stage kept in TC 199, TC $199_+{^+}$ rabbitserum(4:1, 3:2, 2:3 and 1:4), rabbit serum, saline and serum+saline(1:1) were stored at $5^{\circ}C$ for 48 hours. They were than cultured at 37 C for 48 hours to determine their viability. The percentage of ova survived in each storage media was 31, 87, 100, 80, 100, 75 and 83%, respectively.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.185-191
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• 2021

Chicken spermatozoa have the ability to survive in low-temperature environments; however, the effects of low temperature on sperm motility and acrosome damage have not been studied in detail. The present study investigated semen longevity following dilution of rooster semen with Beltsville Poultry Semen Extender (BPSE) and Lake extender in preservation vessels (1.5 mL e-tube and 0.5 mL straw). Spermatozoa motility in the closed-type vessel (0.5 mL straw) was higher than that in the 1.5 mL e-tube on day 3 of preservation (68.6±3.1% vs. 22.1±5.7%). The motility of rooster semen diluted with BPSE in 0.5 mL straw was also higher than that of the Lake extender on day 3 of preservation (57.7±5.6% vs. 37.7±5.4%). Furthermore, acrosome intactness was higher in 0.5 mL straw than in the 1.5 mL e-tube, and the rate of acrosome cap damage increased with preservation days. The present study demonstrates that a closed 0.5-mL straw vessel could be used for low-temperature semen preservation, with an increased motility rate and acrosome integrity in fresh rooster semen.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.136-137
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• 2001

젤리형 해조면류의 유통 및 저장 중에 면가락이 건조되거나 동결하였을 경우 수분이 조직으로부터 분리되어 면의 굵기가 가늘어지면서 딱딱해져 식용하기에 부적당하게 된다. 따라서 이러한 문제를 해결하기 위해서는 먼저 포장을 할 때 적당량의 보존수를 첨가하여 저온 유통을 하여야 한다. 보존수의 첨가 후 저온 유통이 잘 유지될 경우에는 저장 6개월까지는 품질안정성에 문제는 없다. (중략)