Temperature Cryopreservation

Smit Sibinga, C. Th., Das, P.C., Meryman, N.T. (1990). Cryopreservation and Low Temperature Biology in Blood Transfusion. Kluwer Academic Publishers, Dordrecht, Netherlands. 

Figure 2. Viability of NCs (CD 45 ) and hemopoietic stem (CD 34 ) cells after cryopreservation. Legends 1-concentrate, control 2-concentrate, cryopreserved according to own special two-stem program with cold pre-treatment 3-concentrate, cryopreserved according to own special two-step program after treatment at room temperature 4-concentrate, frozen with a rapid plunging into liquid nitrogen after cold pre-treatment with PEO-1500 5-concentrate, frozen by rapid plunging into liquid nitrogen after treatment with PEO-1500 at room temperature.

Digoxin uptake into rat hver shces showed a temperature-dependent component, compatible with the involvement of carrier-mediated uptake mechanisms. Quinine markedly inhibited the uptake of digoxin, in contrast to its diastereomer quinidine, which only slightly inhibited the digoxin uptake in rat liver slices. This stereoselective inhibition is in line with results obtained in isolated rat hepatocytes and isolated perfused rat hvers [90,91]. These results were also found after cryopreservation of the slices, indicating that carrier-specific phenomena can be studied after cryopreservation [92]. 

Culture conditions influence the survival of cells submitted to cryopreservation. To be frozen, cells should be in an active growth phase, with a viability greater than 90% and free of contaminants. The optimal cryopreservation conditions are different for each cell line. When a cell is exposed to low temperatures, ice crystals are generally formed and can disrupt the cell membrane, causing death. Therefore, cells should be treated with a cryoprotector to support the freezing and thawing processes. 

The collection of plant tissue is quite different from animal tissue collection. The discussion of collection of plant and animal tissue by Dessauer et al.2S is detailed and helpful. However, the recommendations for procedures unique to plant tissue collection are somewhat misleading and outdated, especially when tropical collections are involved. Plant tissue can now be collected and transported as either fresh tissue (leaves and/or shoot cuttings) or preserved tissue the latter either as cryopreserved tissue (liquid nitrogen or dry ice) or as dried tissue (air-dried, herbarium-dried, lyophilized, or chemically dried). Ambient-temperature liquid chemical preservation techniques (such as those routinely done for herbarium plant specimens in the tropics) so far have been ineffective in maintaining adequate yields of high-quality DNA.15 It should be stressed again that the manner of collecting plant tissue is dictated by several other factors what macromolecule (DNA, RNA, or isozymes) will be examined, what type of nucleic acid extraction method will be used (or, more impor-... 

NMR relaxation times have also proved useful in probing water mobility in foodstuffs. In some cases, exchange between three water sites, corresponding to bulk, surface and bound water, is used to explain observed relaxation behaviour. Another interesting area is using NMR relaxation times to study the water that does not freeze at the temperatures normally used in cryopreservation. 

Cryopreservation process may be carried out in different ways from placing the cryo-tubes in a Mr. Frosty vessel (NALGENEtm W USA), which ensure a slow temperature decrease by 1°C to the use of computerized cryobath equipment (CryolLogic) with freeze control system. 

LABBfi c, LOIR M, KAUSHiK s and MAISSE G (1993) The influence of both rearing temperature and dietary lipid origin on fatty acid composition of spermatozoan polar lipids in rainbow trout Oncorhynchus my kiss). Effect on sperm cryopreservation tolerance, in Kaushik S J and Luquet P (eds). Fish Nutrition in Practise, Les Colloques No. 61. Paris INRA, 49-59. 

USUKI H, HAMAGucffl M and ISHIOKA H (2002) Effects of developmental stage, seawater concentration and rearing temperature on cryopreservation of Pacific oyster Crassostrea gigas larvae. Fisher Sci, 68, 757-762. 

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