An Experiment with Glycerol‐Frozen Red Blood Cells Stored at ‐80°C for up to 37 years

Background and Objectives: Red cells frozen using 40% W/V glycerol are currently FDA approved for frozen storage at ‐80°C for up to 10 years. Materials and Methods: Red cells frozen with 40% W/V glycerol and stored at ‐80°C for up to 37 years were thawed, deglycerolized, and stored at 4°C for 24 h. Results: Red cells frozen for up to 37 years had mean freeze‐thaw‐wash recovery values of 75%, less than 1% hemolysis, and normal ATP, 2,3‐DPG and P50 levels, and 60% of normal RBC K+ levels. Conclusions: Red cells frozen with 40% W/V glycerol can be stored at ‐80°C for up to 37 years with acceptable in vitro results.