146 Immunity 



A fragment of the placental tissue is removed from the container with sterile 

 forceps and blotted with sterile filter or blotting paper to absorb the toluol and 

 chloroform. It is then placed upon a sterile filter paper and weighed; about 

 0.5 gram should be placed in each of two thimbles. 1.5 cc. of the serum to be 

 tested is cautiously pipetted into one thimble; 1.5 cc. of sterile distilled water 

 into the other. Each is then transferred with forceps to a large tube containing 

 20 cc. of sterile distilled water, and the surface of each fluid is covered with 

 toluol. The tubes are now stood in the thermostat at 37°C. for twenty-four 

 hours, at the end of which time a sample of the fluid in each outer tube is tested 

 by boiling for one minute with ninhydrin (0.2 cc. of a i per cent, solution, to 

 10 cc. of the fluid). The reaction is not read for thirty minutes after boiling. If 

 the conditions are all favorable, i.e., the serum used be from a pregnant woman, 

 the tissue used as substratum be placenta, the enzyme in the serum acts upon 

 the substratum and transforms its albumins to peptones and amino-acids; if the 

 transfusion is perfect in both thimbles, and neither thimble leaks (this has, of 

 course, been previously tested and security can be counted upon now) the fluid 

 surrounding the thimble containing the serum should give a bright blue color or 

 positive reaction, and that surrounding the thimble containing the water no 

 color or a negative reaction. 



By the test we are then able to determine, the substratum being 

 known, whether the serum contains an enzyme capable of acting 

 upon or transforming it; or the enzymic character of the serum being 

 known, it may be possible to tell something about the substratum. 

 The general consensus of opinion is in favor of this reaction as being 

 a useful adjunct in making the diagnosis of pregnancy. But its 

 applicabihty may not be limited to the diagnosis of pregnancy for 

 Freund and Abderhalden,* Frank and Heimanf and many others 

 have used it as an adjunct in the diagnosis of cancer, and various 

 other investigators have shown that modifications of the method 

 makes it applicable for purposes of diagnosis or investigation of other 

 conditions in which defensive enzymes may be present in the blood. 

 For each of these investigations the specific substratum must be pre- 

 pared, and in making each test, the appHcation of the enzyme-con- 

 taining serum to the sterile and appropriate substratum must be 

 made in the tested thimbles with the precautions given above. 



The method is not exclusively adapted for investigation of proteo- 

 lytic enzymes in the serum, but to diastatic and lipolytic ferments 

 as well and Abderhalden has shown that it has uses in these fields. 

 How much importance attaches to the enzymes thus mobilized in 

 the blood in the conditions comprehended in the studies of immunity 

 is as yet uncertain. That there is some bearing of the one upon the 

 other cannot be. doubted. The Abderhalden reactions seem to be 

 less specific than the immunity reactions and appear more as reac- 

 tions en gros, while the immunity reactions previously studied 

 were reactions en detail, but it may well be that this apparent differ- 

 ence depends upon the newness of the former reactions and the 

 crudity of the methods employed as contrasted with the more 

 elaborate study of the latter and the more deUcate methods used. 



* Munch, med Wochenschrift, 1913, xw, 763. 

 t Berl. klin. Wochenschrift, 1913, l, No. 14. 



