WASSERMANN TECHNIQUE 



149 



7. Incubate at 38 C. for 30 minutes. This allows syphilitic antibody, if pres- 

 ent, to bind complement. 



8. As soon as the above mixtures have been made and put in the incubator 

 prepare the "haemolytic system" by adding i volume of 20% emulsion of washed 

 human red cells to 4 volumes of solution of amboceptor paper (8 to 10 Noguchi 

 units of amboceptor paper dissolved in i c.c. of salt solution and then heated to 55 C. 

 for 5 minutes makes a suitable amboceptor solution thus of a paper of which 4 mm. 



CONTROL 1to2 U ' 40 Ito8 I10|6 't'320 lt,640 

 ANTIGEN ANTIGEN ANTIGEN ANTIGEN ANT1OEN ANTIGEN 



FIG. 48. i. Capillary pipette being graduated by drawing up i and 4 drops 

 from a watch-glass, (a) Blue pencil mark of i drop or i volume, (b) Mark of 

 volume of 4 drops. 2. Graduated centrifuge tube containing sodium citrate normal 

 salt solution. 3. Tube with 10 amboceptor units in i c.c. of salt solution. 4. Mix- 

 ture of i volume 20% emulsion red cells and 4 volumes inactivated amboceptor 

 solution. 5. Small glass tubes for Emery test. 6. Method of transferring from 

 tube to tube. 7. Making a Wright U-tube the end "a" to be used as a capillary 

 pipette. 



was the unit we should cut off about 40 mm., place in test-tube and extract the dried 

 serum with i c.c. of salt solution), and place this haemolytic system in incubator 

 alongside the tubes already there. To obtain the washed red cells allow 4 to 10 

 drops of blood to drop into a graduated centrifuge tube containing salt solution to 

 which has been added i % of sodium citrate to prevent coagulation. After shaking, 

 centrifuge. Pour off supernatant fluid, replace with salt solution, again shake and 

 centrifuge this sediment of red cells is to be diluted with 4 volumes of salt solution 

 (20% emulsion). (Incubation hastens sensitization of the red blood cells. Agglutina- 

 tion of red cells also occurs.) 



