The use of sucrose as a cryoprotective agent for the labile sheep erythrocyte-complement component--intermediate...

Sucrose (15% w/v) was found to be a useful agent for cryopreservation of sheep erythrocytes in the intermediate state EAC142. The ordinarilly very labile SAC142, associated with the cells, did not decay to any appreciable degree during periods of storage of 1, 72 or 132 days at -65 to -70 degrees C. Recovery of erythrocytes after freezing and thawing varied. Our best recovery was 76.6% and the poorest was 43.0%. The poorest recoveries were obtained during the latter part of the 132 day experiment after the freezer malfunctioned on day 35 causing a temperature rise to -50 degrees C which lasted for 3 days. The average spontaneous lysis of cells before freezing and thawing was 5.6%. The average spontaneous lysis for cells which had been stored in the frozen state was 6.9%.