88 LABORATORY COURSE IN SERUM STUDY 



Materials : 

 5 Cats 

 2 Rabbits 



Hypodermic syringe 



Fresh guinea pig serum 



Test tubes 



Test tube rack 



Cover slips, microscope slides 



Blood stain (Wright's, Giemsa's or Jenner's) 



LESSON XIII 



ISOBLffiMOLYSIS AND ISOAGGLUTINATION 



TRANSFUSION TESTS 



ANTIBODIES in the blood of one animal capable of acting on 

 the blood of another animal of the same species are called iso- 

 antibodies. Isoagglutinins and isohsemolysins sometimes occur 

 naturally and they can often be made to appear by immunization 

 of animals with the blood of other animals of the same species. 

 They appear with a peculiar regularity which indicates that there 

 are certain groups of individuals within one and the same species 

 whose blood is strictly homologous only with other members of the 

 same group. Among human beings there are four such groups, 

 sharply defined, permanent and hereditary. The existence of 

 these antibodies is of practical importance in connection with 

 blood transfusion because more or less serious results may ensue 

 if a patient is transfused with the blood of a donor who belongs to 

 another group and whose blood is therefore either hsemolytic 

 or hsemagglutinating for the patient, or vice versa. (See table 

 in "Infection and Resistance," page 238.) 



Before transfusion, therefore, unless the urgency of the case for- 

 bids, a number of prospective donors are tested, and one is chosen 

 whose blood does not lake or agglutinate when mixed with that of 

 the patient. The serum of each donor must be tested with the 

 blood cells of the patient and the serum of the patient with the 

 cells of each donor. 



There are two methods of collecting blood for these tests : 



