APPENDIX C 



BLOOD EXAMINATION PREPARATORY TO TRANSFUSION 



Reasons for Making the Examination. We have 

 already called attention to the occurrence of iso- 

 agglutinins, isohaemolysins, and isoprecipitins and 

 their bearing on homologous transfusion. The 

 mere occurrence of these substances in blood serum, 

 to be sure, does not at all prove that isoagglutina- 

 tion or isohaemolysis or isoprecipitation occur when 

 such transfusions are done. In fact we do not even 

 know whether these substances exist at all in the 

 blood plasma. Nevertheless, until we learn other- 

 wise, it will be well to bear in mind the possible 

 danger from this source, and to undertake no 

 transfusions in which examination shows the exist- 

 ence of homologous antibodies. 



Technique of the Tests. It is evident that our 

 tests must be reciprocal, i.e., we must test the 

 serum of both donor and recipient against the 

 blood corpuscles of the other. To do this we col- 

 lect part of the blood from each individual, part 



in citrated salt solution and part in a plain test- 



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