How Blood Type Compatibility Is Determined
AnyTool models the ABO and RhD antigen systems in the browser. For a red-cell transfusion the donor cells’ antigens must be a subset of those the recipient tolerates: O− carries no A, B or RhD antigen and can go to all eight types (universal donor), while AB+ tolerates every antigen and can receive from all eight (universal recipient). Plasma compatibility is computed as the exact reverse, because plasma carries the antibodies (anti-A, anti-B) rather than the antigens — so AB plasma, which has neither antibody, is the universal plasma donor and O plasma can only go to O. Each rule is a pure set comparison in a unit-tested engine, with no server round-trip.
- Red-cell rule: donor antigens must be a subset the recipient tolerates
- O− is the universal red-cell donor; AB+ the universal recipient
- Plasma reverses the rule: AB is universal plasma donor, O the recipient
- Rh-positive cells only go to Rh-positive; Rh-negative suits any Rh
- All eight ABO/Rh types computed client-side with no Calculate button
