2,655 blood units collected from healthy voluntary donors selected according to the criteria of the International Society of Blood Transfusion were tested for the presence of aspirin. This drug was found in 6% of the samples at concentrations ranging from 10 to 200 µg/ml. The clinical implications of these findings are discussed. We also report a case of allergic reaction which could probably be related to the transfusion of blood containing aspirin.

10,853 sera, collected from ‘healthy’ blood donors during the period December 1977 to May 1979, were tested for the presence of penicillinase-sensitive penicillins by a bioassay technique using Bacillus subtilis ATCC 6633 as test organism. Their presence could be demonstrated in 30 sera (0.27%), at concentrations equivalent to 0.2-4.0 µg/ml of penicillin G. The implications of these findings are discussed, particularly the possibility of their relationship to nonhemolytic adverse reactions to transfusion.