[Biochemical values in erythrocytes before freezing and after freezing at low temperatures]

The authors tested three ways of freezing red cell concentrates with glycerin. At -30 degrees C in a deep freezer; on a Planer at the rate of 1 degree C per minute and by immersion into liquid nitrogen to -196 degrees C, stored in cryo-containers in liquid nitrogen. In samples processed in all three ways, incl. the follow-up of glycolysis in red cell concentrates in acid-citrate-dextrose solution, the levels of the following enzymes were assessed: glucose-6-phosphate dehydrogenase, glutathione reductase, pyruvate kinase. In addition also the levels of sodium, potassium, pH and glucose were assessed. The enzyme estimations of all three mentioned enzymes after triple rinsing with saline in the samples immersed in liquid nitrogen at -196 degrees C had the most acceptable values and smallest losses after rinsing.