Bloodwise, I am type A, and Rh-positive.
If this works out, I won’t have to care anymore:
In the 1980s, a team in New York showed that an enzyme from green coffee beans could remove the B antigen from red blood cells. It proved too inefficient for practical use, but Henrik Clausen at the University of Copenhagen in Denmark and colleagues have now screened bacteria and fungi for more powerful enzymes. “The diversity you get in the bacterial kingdom is much higher,” Clausen explains.
The researchers homed in on two enzymes. One, from a gut bacterium called Bacteroides fragilis, removes the B antigen. The other, from Elizabethkingia meningosepticum which causes opportunistic infections in people targets the A antigen. The purified enzymes are highly efficient.
And, less A and B, you’re left with O, the “universal donor” provided you can get past that tricky Rh factor. Plasma, of course, is another matter.