458 IMMUNOLOGY 



Sensitivity. — Kline claims for his later modifications an equal 

 sensitivity and specificity vi^ith the Kolmer and the Kahn reac- 

 tions. According to him, the diagnostic slide test is no less spe- 

 cific than other reliable tests for identification of syphilitic reagin. 



Agreement with Other Tests. — The Kline test has an agree- 

 ment of 95.2 per cent with complement fixation methods. The 

 author claims an agreement of 94.9 per cent v^^ith clinical observa- 

 tions. 



Technique of Tests. — Serum for the test is obtained in the 

 usual way. It is inactivated at 56° C. for 30 minutes in a water 

 bath. The test is made on glass slides. A paraffin ring with an 

 inside diameter of twelve millimeters is placed on a slide. It is 

 most convenient to use slides, two inchas by three inches, containing 

 sixteen such rings. 



Preparation of Antigen. — The antigen emulsion for the diag- 

 nostic procedure is prepared as follows : 



Distilled water 0.85 c.c. 



Cholesterol 1 per cent (absolute ali'ohol) LOO f>,.c. 



Alcoholic extract of beef heart 0.10 c.c. 



Isotonic saline 2.45 c.c. 



The distilled water is placed in a small cork-finish bottle. Choles- 

 terol solution is slowlj^ added down the neck of the bottle and 

 the mixture is rotated for twenty seconds. After addition of the 

 antigen, the mixture is shaken for one minute, throwing the 

 liquid from bottom to stopper each time. The saline solution is 

 added and the shaking repeated, less vigorously than previously, 

 for one minute. The antigen is "cured" for fifteen minutes in a 

 37° C. water bath. 



Technique of Testing. — With the end of the pipette touching 

 the glass, 0.05 to 0.06 c.c. of inactivated serum is placed in the 

 center of the paraffin ring. A drop of antigen containing between 

 0.0075 and 0.0085 c.c. is pla<'ed on top of the serum. The mix- 

 ture is stirred with a toothpick. After four minutes' rotation, the 

 test is completed. 



Reading Test. — A microscopic examination, using a lOx ocular 

 and a 16 mm. objective, is made. Distinct agglutination con- 

 sisting of coarse clumps, is a strongly positive reaction. Finer 

 clumps are interpreted as moderately or weakly positive reac- 



