The equilibrium and non-equilibrium thermal behaviour of aqueous ternary solutions based on complex physiological support media, containing NaCl, and dimethyl sulphoxide or glycerol

Pozner, R.I.; Shepard, M.L.; Cocks, F. H.

doi:10.1007/bf00566270

Cited by 13 publications

(6 citation statements)

References 6 publications

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“…Both the experimental isopleths and the synthesized curves are based on solutions containing NaCl. However, Pozner et al [8] have shown that solutions of glycerol or DMSO in more complex physiological saline exhibit phase behavior that is indistinguishable from that of solutions made with pure NaCl.…”

Section: The Ternary System Glycerol/nacl/watermentioning

confidence: 99%

Comparison of actual vs. synthesized ternary phase diagrams for solutes of cryobiological interest

Kleinhans

Mazur

2007

Cryobiology

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Phase diagrams are of great utility in cryobiology, especially, those consisting of a cryoprotective agent (CPA) dissolved in a physiological salt solution. These ternary phase diagrams consist of plots of the freezing points of increasing concentrations of solutions of cryoprotective agents (CPA) plus NaCl. Because they are time-consuming to generate, ternary diagrams are only available for a small number of CPAs. We wanted to determine whether accurate ternary phase diagrams could be synthesized by adding together the freezing point depressions of binary solutions of CPA/water and NaCl/water which match the corresponding solute molality concentrations in the ternary solution. We begin with a low concentration of a solution of CPA+salt of given R (CPA/salt) weight ratio. Ice formation in that solution is mimicked by withdrawing water from it which increases the concentrations of both the CPA and the NaCl. We compute the individual solute concentrations, determine their freezing points from published binary phase diagrams, and sum the freezing points. These yield the synthesized ternary phase diagram for a solution of given R. They were compared with published experimental ternary phase diagrams for glycerol, dimethyl sulfoxide (DMSO), sucrose, and ethylene glycol (EG) plus NaCl in water. For the first three, the synthesized and experimental phase diagrams agreed closely, with some divergence occurring as wt% concentrations exceeded 30% for DMSO and 55% for glycerol, and sucrose. However, in the case of EG there were substantial differences over nearly the entire range of concentrations which we attribute to systematic errors in the experimental EG data. New experimental EG work will be required to resolve this issue.

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Section: The Ternary System Glycerol/nacl/watermentioning

confidence: 99%

Comparison of actual vs. synthesized ternary phase diagrams for solutes of cryobiological interest

Kleinhans

Mazur

2007

Cryobiology

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“…But they were too few (hematocrit -2%) to have influenced the phase relations significantly. Their contribution to the total solutes in the system is unlikely to be any more than the contribution of the many minor solutes in balanced salt solutions like MEM; Pozner et al (1977) have shown that the introduction of MEM solutes into glycerol-NaCl-water solutions does not detectably alter the phase relations at the R values of concern here.…”

Section: Discussionmentioning

confidence: 72%

“…10-A 1.0 Composition ofthe Liquid Phase ofPartially Frozen Solutions ofGlycerol in Buffered Saline Since Souzu and Mazur (1978) had also performed survival experiments with phosphate-buffered NaCl solutions of the composition shown in Table IB, there was need to determine the phase relations in these buffered solutions. Pozner et al (1977) have shown that the introduction of small quantities of the solutes in Eagle's minimum essential medium (MEM) to glycerol-NaCl solutions does not detectably alter the phase relations at the R values applicable to our study. Therefore, we took the sum of the weights of NaCl and 0.01 M phosphate buffer to be the equivalent weight of sodium chloride alone, assumed that the curves in Fig.…”

Section: Composition Ofthe Liquid Phase Ofpartially Frozen Glycerol-nmentioning

confidence: 75%

Physical-Chemical Basis of the Protection of Slowly Frozen Human Erythrocytes by Glycerol

Rall¹,

Mazur²,

Souzu³

1978

Biophysical Journal

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One theory of freezing damage suggests that slowly cooled cells are killed by being exposed to increasing concentrations of electrolytes as the suspending medium freezes. A corollary to this view is that protective additives such as glycerol protect cells by acting colligatively to reduce the electrolyte concentration at any subzero temperature. Recently published phase-diagram data for the ternary system glycerol-NaCl-water by M. L. Shepard et al. (Cryobiology,13:9-23, 1976), in combination with the data on human red cell survival vs. subzero temperature presented here and in the companion study of Souzu and Mazur (Biophys. J.,23:89-100), permit a precise test of this theory. Appropriate liquidus phase-diagram information for the solutions used in the red cell freezing experiments was obtained by interpolation of the liquidus data of Shepard and his co-workers. The results of phase-diagram analysis of red cell survival indicate that the correlation between the temperature that yields 50% hemolysis (LT(50)) and the electrolyte concentration attained at that temperature in various concentrations of glycerol is poor. With increasing concentrations of glycerol, the cells were killed at progressively lower concentrations of NaCl. For example, the LT(50) for cells frozen in the absence of glycerol corresponds to a NaCl concentration of 12 weight percent (2.4 molal), while for cells frozen in 1.75 M glycerol in buffered saline the LT(50) corresponds to 3.0 weight percent NaCl (1.3 molal). The data, in combination with other findings, lead to two conclusions: (a) The protection from glycerol is due to its colligative ability to reduce the concentration of sodium chloride in the external medium, but (b) the protection is less than that expected from colligative effects; apparently glycerol itself can also be a source of damage, probably because it renders the red cells susceptible to osmotic shock during thawing.

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“…In the calculations and preparation, we have assumed that the molar concentration of the complex of salts (primarily NaCl) in D-PBS (0.1505 M) can be treated as the equivalent molarity of NaCl. With respect to phase diagrams, Pozner et al, [14] have shown that the glycerol/ buffered saline/water phase diagram is indistinguishable from the glycerol/NaCl/water phase diagram. Table 2 gives analogous information on the properties of the experimental EG solutions.…”

Section: Methods and Materials Preparation And Composition Of The Inimentioning

confidence: 99%

14. The temperature of intracellular ice formation in mouse oocytes vs. the unfrozen fraction at that temperature

2007

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We have previously reported [11] that intracellular ice formation (IIF) in mouse oocytes suspended in various concentrations of glycerol and ethylene glycol (EG) occurs at temperatures where the percentage of unfrozen water is about 6% and 12% respectively even though the IIF temperatures varied from −14° to −41°C. However, because of the way the solutions were prepared, the concentrations of salt and glycerol or EG in that unfrozen fraction at IIF were also rather tightly grouped. The experiments reported in the present paper were designed to separate the effects of the unfrozen fraction at IIF from that of the solute concentration in the unfrozen fraction. This separation makes use of two facts. One is that the concentration of solutes in the residual liquid at a given subzero temperature is fixed regardless of their concentration in the initial unfrozen solution. However, second, the fraction unfrozen at a given temperature is dependent on the initial solute concentration. Experimentally, oocytes were suspended in solutions of glycerol/buffered saline and EG/buffered saline of varying total solute concentration with the restriction that the mass ratio of glycerol and EG to salts are held constant. The oocytes were then cooled rapidly enough (20°C/min) to avoid significant osmotic shrinkage, and the temperature at which IIF occurred as noted. When this is done, we find, as previously that the fraction of water remaining unfrozen at the temperature of IIF remains nearly constant at 5 to 8% for both glycerol and EG even though the IIF temperatures vary from −14°C to −50°C. But unlike the previous results, the salt and CPA concentrations in the unfrozen fraction vary by a factor of three. The present procedure for preparing the solutions produces a potentially complicating factor; namely, the cell volumes vary substantially prior to freezing: Substantially greater than isotonic in some solution; substantially smaller in others. However, the data in toto demonstrate that cell volume is not a determining factor in the IIF temperature.

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The equilibrium and non-equilibrium thermal behaviour of aqueous ternary solutions based on complex physiological support media, containing NaCl, and dimethyl sulphoxide or glycerol

Cited by 13 publications

References 6 publications

Comparison of actual vs. synthesized ternary phase diagrams for solutes of cryobiological interest

Comparison of actual vs. synthesized ternary phase diagrams for solutes of cryobiological interest

Physical-Chemical Basis of the Protection of Slowly Frozen Human Erythrocytes by Glycerol

14. The temperature of intracellular ice formation in mouse oocytes vs. the unfrozen fraction at that temperature

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