156 



APPLIED IMMUNOLOGY 



table, by mixing different quantities of the extract of 

 the suspected blood with 0.1 c.c. of suspected blood 

 and 0.03 c.c. of the antiserum. 



0.0001 c.c. 



The tubes containing the above are placed in the 

 incubator at 37° C. for one hour. Then the doses of 

 hemolytic amboceptor and 5 per cent, sheep's cor- 

 puscles are added and the tubes again incubated for 

 one hour. If 0.01 c.c. of the extract of blood prevents 

 haemolysis, the test can be regarded as positive for 

 human blood. 



Antisera for blood of various animals can be pre- 

 pared in the same way and the extract of unknown 

 blood tested with them. 



