Background and Objectives: Red cells frozen using 40% W/V glycerol are curr
ently FDA approved for frozen storage at -80 degreesC for up to 10 years. M
aterials and Methods: Red cells frozen with 40% W/V glycerol and stored at
-80 degreesC for up to 37 years were thawed, deglycerolized, and stored at
4 degreesC 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 KC levels. Conclusions:
Red cells frozen with 40% W/V glycerol can be stored at -80 degreesC for u
p to 37 years with acceptable in vitro results.