Demster

Patient is group O in forward typing but the reverse demonstrated no reactions in both A1 cells and B cells. I tried incubating the serum with the reagent red cells at room temperature for 15-30 minutes but still yielding no reactions. I tried another approached by incubating the serum with the reagent red cells at 4o C for 15-30 minutes but only got an M+ on A1 cells but still no reactions in B cells. What do you think is causing this? Thanks!