264 FERMENTS AND ANTIFERMENTS 



FERMENT REACTIONS 

 ANTITRYPSIN TEST 



Bergmann and Meyer 1 have devised a test for estimating the titer 

 of antitrypsin that possesses value in determining the presence of tryp- 

 tic ferment hi the blood-serum and in the intestinal and stomach con- 

 tents. The test may also prove of value in making a functional study 

 of the pancreas. At present it is regarded by some as an aid to the 

 diagnosis of cancer, and it may also be of service in establishing the 

 diagnosis and prognosis of suppurative processes. 



Solution of Trypsin. This is made by dissolving 0.5 gm. of pure 

 trypsin (Griibler) in 50 c.c. of NaCl solution and adding 0.5 c.c. of normal 

 soda solution; make up to 500 c.c. with physiologic salt solution. 



Casein Solution. Dissolve one gram of pure casein in 100 c.c. of 

 sodium hydroxid solution with the aid of gentle heat. Neutralize to 

 litmus with ^ hydrochloric acid solution and dilute with physiologic 

 salt solution up to 500 c.c. Filter and sterilize in an Arnold sterilizer. 

 Preserve in the refrigerator. 



Acetic Acid Solution. To 5 c.c. of acetic acid (c. p.), add 45 c.c. 

 of absolute alcohol and 50 c.c. of distilled water. 



The patient's serum must be fresh, and should be diluted 20 times 

 with salt solution. Dose, 0.2 c.c. 



Technic. A titration of the trypsin solution must precede the test 

 proper. Into each of several small test-tubes place increasing amounts 

 of trypsin solution, as, for example, 0.1, 0.2, 0.4, 0.6, 0.8, and 1.0 c.c. 

 Add 2 c.c. of the casein solution to each tube; shake carefully and place 

 in an incubator or water-bath for half an hour at 50 C. Then add 

 three or four drops of the acetic acid solution to each tube, and observe 

 which tube first shows cloudiness after a few minutes. The tube con- 

 taining the smallest amount of trypsin and which remains perfectly 

 clear contains enough trypsin fully to digest the 2 c.c. of casein solution. 



Into each of six small test-tubes now place 0.2 c.c. of the 1 : 20 dilu- 

 tion of the patient's serum, and increasing amounts of the trypsin solu- 

 tion, beginning with the completely digesting dose, as determined above, 

 and increasing by 0.1 c.c. Add 2 c.c. of casein solution to each tube, 

 and bring all tubes to a like volume by the addition of normal salt solu- 

 tion. Shake gently, and incubate at 50 C. for half an hour. Add 



1 Berl. klin. Wochenschr., 1908, No. 37. 



