The blood type of B negative is also uncommon, occurring in "2% of Caucasian, 1% of African American, 0.4% of Asian and 1% of Latino American" populations, according to the American Red Cross.

Type B: Has B antigens on the RBCs and anti-A antibodies ... while someone with A-negative blood lacks the Rh factor. The ABO System shows the compatibility between donors and recipients based ...

The American Red Cross has an urgent need for blood donors of all types, especially O negative, A negative and B negative, as fewer donations than expected were given in the first half of summer.