1 70 THE TECHNIQUE OF COMPLEMENT FIXATION. 



3. Five per cent, sheep's red blood corpuscles. 



4. and 5. The inactivated serum for examination and an inactive normal control 

 serum. 



Four tubes are required for the reaction: 



First tube: 0.2 serum, i.o c.c. organ extract in dilution i : 5 and i c.c. comple- 

 ment i : 10. 



Second tube: Same as i, but instead of organ extract, 0.85 per cent, sodium chloride. 



Third tube: Two-tenths normal serum, organ extract and complement as in tube i. 



Fourth tube: Same as third tube, but instead of organ extract 0.85 per cent, saline. 



The tubes are placed into incubator for one-half hour and then i c.c. of a 5 per cent, 

 red blood cell emulsion is added. 



After fifteen to forty-five minutes tubes 2, 3, and 4 show hemolysis, while tube i 

 shows hemolysis or not, depending upon the absence or presence of syphilis. 



Lipemic serum is not suitable for the reaction. 



Bauer asserts that this method gives results identical with those obtained by the 

 Wassermann tests. Heinrichs, Bering and others confirm Bauer's findings. 



If the alcoholic extract made from luetic or normal human or animal organs is diluted 

 with physiological saline, a milky opalescent solution results. The grade of turbidity of 

 the resulting solution depends upon the rapidity with which the saline for dilution is 

 added. If the first 15 to 20 drops of the latter are added slowly, the resulting solution 

 will be much more turbid than if the saline is added quickly. Sachs first observed 

 this phenomenon and stated that the stronger the turbidity the more active is the power 

 of the antigen to bind complement. 



The editor has worked with the guinea-pig's heart extract in several 

 thousand tests and has found it giving perfect results. The amount usually 

 used is 0.2 to o.i c.c. in the first test-tube and o.i to 0.05 in the second test- 

 tube as determined by titration. When the antigen is diluted (either i : 5 or 

 i : 10) the first c.c. of saline should be added drop by drop and shaken, thus 

 producing a distinctly opalescent solution. 



The author refrains from describing any other modifications in detail as 

 they have not been verified sufficiently to merit a position in this important 

 field of serum diagnosis. This holds true especially for the recently advised 

 quick and easy short cuts by the use of the various ingredients dried on 

 paper. In order, however, that one may acquaint himself with these modifica- 

 tions, if he so desires, the reference of their original publications are here 

 given. 



Tschernogubow, Berlin. Klin. Wochenschr., 1908, No. 47, and Deutsche 

 Med. Wochenschr., 1909, No. 15. 



Weidanz, Deutsche Med. Wochenschr., 1908, No. 48, Refer. 



Noguchi, Journal of Americ. Medic. Associat, 1908, No. 22, u. Munch. 

 Med. Woch., 1909, No. 10. 



Hecht, Wien. Klin. Wochenschr., 1908, No. 50, and 1909, No. 10. 



Fleming, Lancet, 1909, 4474. 



Stern, Zeitschr. f. Immunitatsforschung, 1909, Bd. I. 



Bauer, Deutsche Med. Wochenschr., 1909, No. 10. 



