Dependability of ABO findings in stored blood samples

Report on the occurrence of "acquired" A or B in stored blood samples. This bacterial alteration is of importance when an indirect experimental investigation with the absorption-elution technique is needed in advanced cases of hemolysis. One has to consider this disturbing factor in identification tests (alcoholic blood samples). In dried blood stains we did not notice this problem, but it has to be taken into account in genitals stains.