OLD TUBERCULIN 473 



NOGUCHI MODIFICATION or THE WASSERMANN TEST. The Noguchi 

 test for syphilis is a modification and simplification of the Wassermann 

 test and involves the use of "amboceptor paper," a solution of "antigen" 

 and " complement," the latter to be obtained from the blood of a guinea-pig. 



The amboceptor is obtained by injecting washed human blood-cor- 

 puscles (erythrocytes) into rabbits, at intervals of from five to seven days, 

 over a period of five or six weeks. Ten days are allowed to elapse before 

 the last injection. The rabbits are then bled and the serum collected. 

 Filter paper is now saturated with this serum and allowed to dry. The 

 paper is cut into strips and set aside until wanted for use. In this form 

 amboceptor will keep for a considerable length of time. 



Amboceptor paper is standardized by measuring its specific activity. 

 The measurement of specific activity consists in finding the amount of 

 amboceptor necessary to cause hemolysis in i mil of suspended human 

 red corpuscles, one drop of blood in 4 mils normal saline solution with 0.02 

 mil of fresh guinea-pig serum. This is incubated at a temperature of 

 37C. for one hour. The quantity of paper necessary to cause hemolysis 

 under these conditions is known as one unit. In the syphilis test two 

 units are used. 



ANTIGEN. This is made by rubbing liver and heart tissue with sand 

 and extracting with absolute alcohol. Macerate 10 Gm. of tissue in 

 100 mils of alcohol for one week at 37C., shaking the container every day. 

 Dissolve the resulting extract in ether. Pour this solution into a large 

 quantity of acetone. The acetone precipitates certain lipqid substances 

 which are then collected and redissolved in methyl alcohol, in ratio of 3 

 per cent. This constitutes the antigen solution. For use mix i part 

 of this with 9 parts, 0.9 per cent, sodium chloride solution. This dilution 

 should not cause hemolysis in an amount of 0.4 mil and 0.4 mil should not 

 inhibit hemolysis. 



D. VACCINATION FOR DIAGNOSIS 



Old Tuberculin Tuberculin alt Koch Concentrated Tuberculin 

 Crude Tuberculin. Koch's original tuberculin is prepared from glycerin 

 bouillon cultures of the tubercle bacillus by evaporating to one-tenth 

 the original volume, sterilizing at iooC. for one hour, and filtering 

 through a Berkefeld filter. It is a clear brown syrupy liquid, with a 

 high content of glycerin and a characteristic odor. 



For diagnosis, old tuberculin may be used by hypodermic injection to 

 show a reaction at the site of application (local), at site of suspected 

 disease (focal) or generally (constitutionally). If positive, the tuberculin 

 reaction merely indicates that the patient has at some time been infected 

 with tuberculosis and not necessarily that he has clinical tuberculosis. 

 Careful series of necropsies confirm the results of the use of tuberculin 



