40 Comparison of slow and rapid freezing in freeze-dried ram spermatozoa

2020 ◽  
Vol 32 (2) ◽  
pp. 146
Author(s):  
L. Palazzese ◽  
D. A. Anzalone ◽  
P. Toschi ◽  
P. Loi
Keyword(s):  
Liquid Nitrogen ◽  
Rapid Freezing ◽  
Cell Stage ◽  
Food Industries ◽  
Long Term Storage ◽  
Freeze Dried ◽  
Cheap Alternative ◽  
Group 2 ◽  
Term Storage

Semen lyophilisation is an interesting technique that might be a cheap alternative to long-term storage in liquid nitrogen. The first significant result of this method was achieved by Wakayama and Yanagimachi in the 1998 and demonstrated, for the first time, the birth of healthy mouse pups from epididymal freeze-dried (mouse) spermatozoa. The authors follow the lyophilisation technique, commonly used in the pharmaceutical and food industries, namely, deep freezing, which requires direct immersion of the semen sample into liquid nitrogen before vacuum drying. In this work, we focused on the freezing phase to improve and make the technique more reliable. We compared two protocols: 1) rapid freezing, where the semen is plunged directly into liquid nitrogen (LN group), and 2) slow freezing, where the sample is frozen with a freezing rate of 1°C min−1 until −50°C (SL group). Then, both frozen samples were lyophilized. Subsequently, after an interval ranging between 1 and 3 months, dry spermatozoa from LN and SL groups were used for intracytoplasmic sperm injection (ICSI), and the embryo development was evaluated at 24h (2-cell stage) and 7 days (expanded blastocyst) post-ICSI. Moreover, acrosome integrity was evaluated with Pisum sativum agglutinin (PSA) staining on part of the semen, immediately after freezing. The LN-group semen showed the acrosome completely melted, whereas the SL group showed better integrity of the acrosome, which was comparable to that of the normal frozen (vital) spermatozoa. At 24h post-ICSI the number of cleaved embryos in the SL group was higher than in the LN group (42/100 (42%) vs. 19/75 (25.3%), SL and LN, respectively; P=0.0253). The blastocyst rate 7 days after ICSI in the SL group was higher (7/100 (7%) than that in the LN group (2/75 (2.7%); P=0.0238). Our data show that lyophilisation can be conveniently achieved in ram spermatozoa without liquid nitrogen, thus simplifying the procedure. These data support the idea that lyophilisation might be a valuable and cheaper alternative to liquid nitrogen for long-term storage of ram semen.

scholarly journals CRYOPRESERVATION OF TRUE-SEED AND EMBRYO OF MAIZE AND SOYBEAN FOR LONG-TERM STORAGE

2016 ◽  
Vol 2 (2) ◽  
pp. 31
Author(s):  
Enny Sudarmonowati ◽  
I. Fitryatmi ◽  
S. Sadjad
Keyword(s):  
Liquid Nitrogen ◽  
Rapid Freezing ◽  
Soybean Seeds ◽  
Long Term Storage ◽  
Significant Difference ◽  
Long Term Preservation ◽  
Term Storage ◽  
Cryoprotectant Solution ◽  
Excised Embryos

<br />Study on cryopreservation of Indonesian local cultivars and improved  varieties of maize and soybean has never been done. This method may be used for long-term preservation of seeds of maize and soybean. In this study, the method was applied to maize and soybean, Arjuna and Wilis respectively, as a model for preserving germplasm of ortodox seeds. Whole seeds and excised embryos of both varieties were subjected to two methods of cryopreservation, i.e., two-stage cooling and rapid freezing with or without 15% dimethyl sulfoxide (DMSO) as cryoprotectant solution prior to immersion in liquid nitrogen (-196oC). Results indicated that there was no significant difference between the use of DMSO for both species in terms of viability, although pretreatment in DMSO was slightly reduced the percentage of viability of both species. Slow freezing to -30oC prior to immersion in the liquid nitrogen could give as high as 76.67% and 51.67% surviving whole seeds of maize and soybean, respectively. Preserving excised embryos of maize in the liquid nitrogen using either slow or rapid freezing significantly reduced the percentage of viability from 20-76.67% to 5-18.33% (four folds) depending on treatments applied. Results also showed that one day or 15 minutes of immersion of samples in the liquid nitrogen gave rise to similar values of viability of maize and soybean, i.e., 20-60% and 20-51.67%, respectively depending on  treatments applied. These results implied that for long-term storage of maize and soybean seeds as they could survive at the rate of 76.67% and 51.67% respectively, the seed can be treated by prefreezing to -30oC<br />without the presence of DMSO prior to immersion in liquid nitrogen.<br /><br />

scholarly journals CRYOPRESERVATION OF TRUE-SEED AND EMBRYO OF MAIZE AND SOYBEAN FOR LONG-TERM STORAGE

2016 ◽  
Vol 2 (2) ◽  
pp. 31
Author(s):  
Enny Sudarmonowati ◽  
I. Fitryatmi ◽  
S. Sadjad
Keyword(s):  
Liquid Nitrogen ◽  
Rapid Freezing ◽  
Soybean Seeds ◽  
Long Term Storage ◽  
Significant Difference ◽  
Long Term Preservation ◽  
Term Storage ◽  
Cryoprotectant Solution ◽  
Excised Embryos

<br />Study on cryopreservation of Indonesian local cultivars and improved  varieties of maize and soybean has never been done. This method may be used for long-term preservation of seeds of maize and soybean. In this study, the method was applied to maize and soybean, Arjuna and Wilis respectively, as a model for preserving germplasm of ortodox seeds. Whole seeds and excised embryos of both varieties were subjected to two methods of cryopreservation, i.e., two-stage cooling and rapid freezing with or without 15% dimethyl sulfoxide (DMSO) as cryoprotectant solution prior to immersion in liquid nitrogen (-196oC). Results indicated that there was no significant difference between the use of DMSO for both species in terms of viability, although pretreatment in DMSO was slightly reduced the percentage of viability of both species. Slow freezing to -30oC prior to immersion in the liquid nitrogen could give as high as 76.67% and 51.67% surviving whole seeds of maize and soybean, respectively. Preserving excised embryos of maize in the liquid nitrogen using either slow or rapid freezing significantly reduced the percentage of viability from 20-76.67% to 5-18.33% (four folds) depending on treatments applied. Results also showed that one day or 15 minutes of immersion of samples in the liquid nitrogen gave rise to similar values of viability of maize and soybean, i.e., 20-60% and 20-51.67%, respectively depending on  treatments applied. These results implied that for long-term storage of maize and soybean seeds as they could survive at the rate of 76.67% and 51.67% respectively, the seed can be treated by prefreezing to -30oC<br />without the presence of DMSO prior to immersion in liquid nitrogen.<br /><br />

Somatic polyembryogenesis in embryogenic cell masses of Piceaabies (Norway spruce) and Pinustaeda (loblolly pine) after thawing from liquid nitrogen

1987 ◽  
Vol 17 (9) ◽  
pp. 1130-1134 ◽  
Author(s):  
P. K. Gupta ◽  
D. J. Durzan ◽  
B.J. Finkle
Keyword(s):  
Liquid Nitrogen ◽  
Loblolly Pine ◽  
Somatic Embryos ◽  
Cell Mass ◽  
Embryogenic Cell ◽  
Long Term Storage ◽  
Embryogenic Cell Lines ◽  
Improvement Programs ◽  
Term Storage

We describe a method for the possible cryopreservation of embryogenic callus of Piceaabies and Pinustaeda at −196 °C and the regeneration of somatic embryos from thawed cells of subcultured embryonal–suspensor masses. Piceaabies and Pinustaeda were frozen without cryoprotective agent, in the presence of dimethyl sulfoxide (10%), or in a mixture of polyethylene glycol, glucose, and dimethylsulfoxide (10, 8, and 10% w/v, respectively). Cell masses placed in plastic vials or aluminum envelopes were frozen at 1 °C/min to −30 °C and then immersed for 10 min in liquid nitrogen. Cells were thawed rapidly and placed on modified MS subculture medium. Six to seven somatic embryos per gram of fresh weight were regenerated from each piece of frozen cell mass as compared with 12–13 embryos per gram from unfrozen cells. Post-thaw cell growth was inhibited initially by up to 5 weeks. Inhibition was reversed after the third 10-day subculture. Results suggest that the long-term storage of embryogenic cell lines in liquid nitrogen may be feasible for tree improvement programs in circumstances where testing of progeny may take several years.

scholarly journals Microbial occurrence in liquid nitrogen storage tanks: a challenge for cryobanking?

2021 ◽  
Author(s):  
Felizitas Bajerski ◽  
Manuela Nagel ◽  
Joerg Overmann
Keyword(s):  
Risk Assessment ◽  
Quality Management ◽  
Liquid Nitrogen ◽  
Potential Risk ◽  
Biological Materials ◽  
Cross Contamination ◽  
Storage Tanks ◽  
Long Term Storage ◽  
Term Storage

Abstract Modern biobanks maintain valuable living materials for medical diagnostics, reproduction medicine, and conservation purposes. To guarantee high quality during long-term storage and to avoid metabolic activities, cryostorage is often conducted in the N2 vapour phase or in liquid nitrogen (LN) at temperatures below − 150 °C. One potential risk of cryostorage is microbial cross contamination in the LN storage tanks. The current review summarises data on the occurrence of microorganisms that may compromise the safety and quality of biological materials during long-term storage. We assess the potential for the microbial contamination of LN in storage tanks holding different biological materials based on the detection by culture-based and molecular approaches. The samples themselves, the LN, the human microbiome, and the surrounding environment are possible routes of contamination and can cause cross contaminations via the LN phase. In general, the results showed that LN is typically not the source of major contaminations and only a few studies provided evidence for a risk of microbial cross contamination. So far, culture-based and culture-independent techniques detected only low amounts of microbial cells, indicating that cross contamination may occur at a very low frequency. To further minimise the potential risk of microbial cross contaminations, we recommend reducing the formation of ice crystals in cryotanks that can entrap environmental microorganisms and using sealed or second sample packing. A short survey demonstrated the awareness for microbial contaminations of storage containers among different culture collections. Although most participants consider the risk of cross contaminations in LN storage tanks as low, they prevent potential contaminations by using sealed devices and − 150 °C freezers. It is concluded that the overall risk for cross contaminations in biobanks is relatively low when following standard operating procedures (SOPs). We evaluated the potential sources in detail and summarised our results in a risk assessment spreadsheet which can be used for the quality management of biobanks. Key points • Identification of potential contaminants and their sources in LN storage tanks. • Recommendations to reduce this risk of LN storage tank contamination. • Development of a risk assessment spreadsheet to support quality management.

scholarly journals Development of cryopreservation methods of seed of Nepeta cataria

2021 ◽  
Vol 102 (2) ◽  
pp. 37-42
Author(s):  
Margarita Ishmuratova ◽  
◽  
Damirzhan Baigarayev ◽  
Saltanat Tleukenova ◽  
Elena Gavrilkova ◽  
...  
Keyword(s):  
Liquid Nitrogen ◽  
Room Temperature ◽  
Seed Viability ◽  
Positive Temperature ◽  
Seed Rate ◽  
Nepeta Cataria ◽  
Long Term Storage ◽  
Medical Plant ◽  
Term Storage

This article presents the summarized data on cryopreservation of seeds of the medical plant Nepeta cataria. Cryopreservation is a highly promising method for saving of seed materials, allowing to organize long-term storage without viability loss. The purpose of present work is to optimize conditions of cryopreservation of seed materials of Nepeta cataria. Assessment of seed survival rate in the storage showed a linear decrease in seed viability and energy of germination. After 30 months of storage at the low positive temperature (+5 ºC) in paper pack seed rate decreased to 12.0 % and energy of germination to 11.2 %; after 4 years of storage seeds lost viability. During conduction of research the type of container, condition of thawing, optimal moisture of seeds and cryoprotectants are optimized. The optimal container for cryopreservation in liquid nitrogen was plastic cryo tubes; defrosting at room temperature. The best seed rate is found at moisture 3 %; the best cryoprotectant was glucose, the optimal concentration was 15 %. The result of the research is used for creation of the long-term storage medicinal cultures’ seed bank in the liquid nitrogen.

scholarly journals Cryopreservation of Shoot Tips and Pollen of Potato

2017 ◽  
Vol 76 (1) ◽  
pp. 75-80
Author(s):  
Paulina Smyda-Dajmund
Keyword(s):  
Liquid Nitrogen ◽  
Shoot Tips ◽  
Popular Method ◽  
Long Term Storage ◽  
Term Storage ◽  
Direct Immersion

Abstract Cryopreservation is a frequently used method of long-term storage of potato meristems and pollen in liquid nitrogen (LN) in temperature of -196°C. This technique allows for theoretically unlimited storage of potato material. The most popular method of potato shoot tips preservation is cryopreservation by the solidification of liquids without crystallization (vitrification).The best method of pollen conservation is its direct immersion in LN. The successful regeneration after vitrification is genotype-dependent, which require optimization of protocol.

scholarly journals Design of a new lyoprotectant increasing freeze-dried Lactobacillus strain survival to long-term storage

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Aurore Bodzen ◽  
Audrey Jossier ◽  
Sébastien Dupont ◽  
Pierre-Yves Mousset ◽  
Laurent Beney ◽  
...  
Keyword(s):  
Water Content ◽  
Water Activity ◽  
Freeze Drying ◽  
Sucrose Solution ◽  
Bound Water ◽  
Long Term Storage ◽  
Freeze Dried ◽  
Micellar Casein ◽  
Term Storage

Abstract Background Stabilization of freeze-dried lactic acid bacteria during long-term storage is challenging for the food industry. Water activity of the lyophilizates is clearly related to the water availability and maintaining a low aw during storage allows to increase bacteria viability. The aim of this study was to achieve a low water activity after freeze-drying and subsequently during long-term storage through the design of a lyoprotectant. Indeed, for the same water content as sucrose (commonly used lyoprotectant), water activity is lower for some components such as whey, micellar casein or inulin. We hypothesized that the addition of these components in a lyoprotectant, with a higher bound water content than sucrose would improve lactobacilli strains survival to long-term storage. Therefore, in this study, 5% whey (w/v), 5% micellar casein (w/v) or 5% inulin (w/v) were added to a 5% sucrose solution (w/v) and compared with a lyoprotectant only composed of 5% sucrose (w/v). Protective effect of the four lyoprotectants was assessed measuring Lactiplantibacillus plantarum CNCM I-4459 survival and water activity after freeze-drying and during 9 months storage at 25 °C. Results The addition whey and inulin were not effective in increasing Lactiplantibacillus plantarum CNCM I-4459 survival to long-term-storage (4 log reduction at 9 months storage). However, the addition of micellar casein to sucrose increased drastically the protective effect of the lyoprotectant (3.6 log i.e. 0.4 log reduction at 9 months storage). Comparing to a lyoprotectant containing whey or inulin, a lyoprotectant containing micellar casein resulted in a lower water activity after freeze-drying and its maintenance during storage (0.13 ± 0.05). Conclusions The addition of micellar casein to a sucrose solution, contrary to the addition of whey and inulin, resulted in a higher bacterial viability to long-term storage. Indeed, for the same water content as the others lyoprotectants, a significant lower water activity was obtained with micellar casein during storage. Probably due to high bound water content of micellar casein, less water could be available for chemical degradation reactions, responsible for bacterial damages during long-term storage. Therefore, the addition of this component to a sucrose solution could be an effective strategy for dried bacteria stabilization during long-term storage.

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