204 



OPSONIC INDEX 



foundation. Aside from the 10 per cent, of chances of technical error 

 in making an opsonin measurement, other factors may be present that 

 are entirely beyond control and cannot be measured by the immunisator, 

 and that may seriously affect the value of the opsonic index. 



3. As a diagnostic procedure, Wright has shown that the opsonins 

 possess a certain specificity, and that in a given infection a low index 



Diagnosis \ 



A9S 



Cult'jre; 



Month 





S 



Day of 

 Month 



37 





2.0 

 .9 



3 



! 





.1 



1.0', 

 .9 



.8 

 .7. 

 .6 . 

 .5 

 .4 



.2. 

 .1 . 



FIG. 56. AN OPSONIC INDEX CHART. 



for a certain microorganism indicates that this organism is probably the 

 etiologic factor. This possibility is strengthened if the opsonic index 

 for this microorganism is increased by careful manipulation or exercise 

 of the diseased part, when auto-inoculation occurs, with consequent 

 increase of opsonin. 



4. In prognosis the opsonic index may have some value in deciding 





