The Ability of Pectins to Modulate the Action of Glycerol In the Freezing of Nucleated Cells

Pectins have a large number of active -OH and -COOH groups (3), suggesting the presence of this group of substances specific cryoprotective effect.

This research is aimed at studying the ability of pectins (zosteran, apple pectin АU-701, E-440) to change the freezing temperature of glycerol, which can increase the effect in the cryopreservation of nuclear cells.

Using the cryoscopic method we studied the ability of pectins (zosteran, apple pectin AU-701, E-440) to change the freezing temperature of glycerol. Heparinized venous blood was frozen under the protection of a complex cryoprotectant and stored in an electric freezer at -80 degree C for 1 day.

The research shows that pectins in a concentration of 0.6 - 1.0% increase in varying degrees the osmolality of the glycerol solution, which helps to low its freezing temperature. According to the viability of leukocytes which had been frozen to -80 degree C in glycerol habitat and one of the pectins, we found out that all pectins in concentration (0.6%) are capable to increase the cryoprotective effect of glycerol.

The obtained data on the preservation of leukocyte membranes and the phagocytic activity of neutrophils after freezing) in glycerol habitat and glycerol with pectin confirm the authors' supposition that decrease in freezing temperature of a solution of glycerol in the presence of pectin helps to reduce the risk of cell damage during freezing. Apple pectin AU-701 is able to strengthen the cryoprotective effect of glycerol in a greater grade. It is possible due to the large number of hydroxyl and carboxyl groups (the galacturonic acid content is 95%) and the presence of methyl groups in the pectin molecule (the degree of methyl etherification is 38-40%). These groups are the most often found in the molecules of effective cryoprotectants.