Agglutination Reaction. 



359 



KMn0 4 (i c.c. = 2 mg. Ca); add the filter paper to flask and 

 titrate to find end point. Tenth normal oxalic acid (made from 

 powdered oxalic acid dried over a mixture of hydrated and de- 

 hydrated oxalic acid) is used to standize the permanganate (as 

 well as the NaOH for P analysis). 



P Analysis. — Take aliquot containing 5-10 mg. P in a 200 

 c.c. pyrex flask; dilute to 100 c.c; add 10 c.c. HN0 3 and 1 drop 

 brom-phenol blue; neutralize with ammonia; add 20 c.c. acid 

 ammonium molybdate solution (usual formula); heat to 65 0 ; 

 shake 5 minutes; filter (the filtrate should turn methyl violet 

 green). Wash until there is no titratable acidity in wash water; 

 transfer paper and precipitate back to flask; run in 0.1 N NaOH 

 until precipitate dissolves; boil 5 minutes; add }4 c.c. phenolph- 

 thalein and titrate to colorless with 0.1 N HC1. 1 c.c. alkali cor- 

 responds to 0.1 194 mg. P. 



174 (1921) 



The agglutination reaction in the diagnosis of tuberculosis. 



By W. P. LARSON, E. N. NELSON and PU YUNG CHANG. 



[From the Department 0} Bacteriology and Immunology, University 

 oj Minnesota, Minneapolis, Minn.] 



Many attempts have been made in the past to make use of the 

 agglutination reaction in the diagnosis of tuberculosis. The test 

 has been found unsatisfactory largely because of the fact that the 

 tubercle bacilli grow in adherent masses from which it has been 

 difficult to prepare the homogeneous suspensions necessary for 

 carrying out the test. 



In the year 191 8 Larson, Hartzell and Diehl 1 described a 

 method of emulsifying and disrupting bacteria by subjecting them 

 to the influence of carbon dioxide under high pressure, after which 

 the pressure was suddenly released, causing a disruption of the 

 organisms as a result of the rapid escape of the gas with which 

 they were filled. 



Tubercle bacilli grown on glycerine broth or glycerine agar are 

 suspended in distilled water and placed in the apparatus where 



1 Jour. Inf. Diseases, 1918, xxii, 271-279. 



