A blood banker needed to confirm the presence of anti-P1 in a patient sample. Fresh reagent RBCs were not available so an old panel that contained cells positive for P1 was used. No cells positive for the antigen reacted at any phase of the AHG test, whereas cells from the screening cells sHowed specificity for the presence of antiP1. What is a possible explanation for this?
a) The blood banker omitted an enhancement reagent.
b) The patient expresses the p phenotype.
c) P1 antigen deteriorates rapidly on storage.
d) The blood banker forgot to add AHG.