Some can and do, but there are some challenges for it being a general solution:

- Some people don't know they need rare blood (because they didn't have the antibody at first, then found they had it later).

- Some people may donate blood to have it available for a need, then a need comes up (either themselves or someone else). At that point, the blood gets used up - what happens when the need is greater than the number of stored units?

- Some people may not be able to donate. We had a patient with something north of 9 antibodies who, due to sickle cell disease wasn't able to donate - (banking blood for long term storage requires freezing, which doesn't work with blood from patients with sickle cell disease).