Osmotic fragility changes in preserved blood: measurements by coil planet centrifuge and parpart methods.

The coil planet centrifuge (CPC) can be used to measure the osmotic fragility of erythrocytes. Fragility measured by this method alters when different salts are used. The CPC and Parpart methods were used to measure the changes during storage in red cell osmotic fragility in ACD or CPD blood with or without adenine. More marked changes were detected by the CPC method, especially in old cells. The changes of fragility of erythrocytes during storage seem to occur mainly in old cells. Adenine is effective in preventing such changes.