Stability and functional properties of haemoglobin freeze-dried in the presence of four protective substances after prolonged storage: dose-effect relationships.

Freeze-dried haemoglobin samples protected during the desiccation by sucrose, arginine aspartate, lysine aspartate, sodium-zinc EDTA and Ficoll 70 have been stored under air at 4 degrees C for 15 months. The analysis showed that sufficient concentrations of sucrose and of the amino-acid salts prevent the oxidation of haemoglobin and maintain its functional properties. Relationships between the concentrations of these compounds and the methaemoglobin levels before and after storage were calculated. They define theoretical concentration points where methaemoglobin would not be found after storage. Sucrose is slightly more effective than the amino-acid, but oppositely, EDTA and Ficoll 70 do not allow prolonged storage of freeze-dried haemoglobin.