OPSONINS AND VACCINE THERAPY 



339 



ences of opinion still exist. Hektoen and Ruediger 17 who have 

 investigated the question attribute to opsonins a complex constitu- 

 tion. They believe them to possess a thermostable haptophore group 

 and a thermolabile "opsonophore" group and that heating beyond 

 a definite temperature converts the opsonins into opsonoids by 

 destruction or alteration of the ' ' opsonophore " group. This view 

 is not shared by all workers and has been disputed by Bullock 

 and Atkin. 18 



The Technique of Wright. The three factors necessary for the 

 performance of an opsonic test are (1) the blood serum to be tested; 

 (2) an even emulsion of bacteria, and (3) leucocytes. 



FIG. 40. WRIGHT'S CAPSULE FOR COLLECTING BLOOD. 



(1) Blood serum is obtained by bleeding from the finger and 

 receiving the blood into glass capsules (Fig. 40). These are sealed 

 at both ends; the blood is allowed to clot; and the separation of 

 serum is hastened by a few revolutions of a centrifuge. 



(2) The bacterial emulsion is obtained by rubbing up a few 

 loopfuls of a twenty-four-hour slant agar culture with a little 

 physiological salt solution (0.85 per cent) in a watch glass. A very 



FIG. 41. PIPETTE FOR OPSONIC WORK. 



small amount of salt solution is used at first and more is gradually 

 added, drop by drop, as the emulsion becomes more even. The final 

 breaking up of the smaller clumps is best accomplished by cutting 

 off very squarely the end of a capillary pipette, placing it perpen- 

 dicularly against the bottom of the watch glass, and sucking the 

 emulsion in and out through the narrow chink thus formed. 

 (Fig. 41.) 



17 Hektoen and Euediger, Jour, of Inf. Dis., ii, 1905. 



18 Bullock and Atldn, Proc. Koyal Soc., Ixxiv, 1905. 



