96 TISSUE FERMENTS 



Mere mention can be given a very interesting practical 

 application of the optical method, that of its employment in 

 the diagnosis of pregnancy. Abderhalden started out with 

 the idea that if it be correct, as many gynecologists testify, 

 that cellular elements of the chorionic villi pass into the cir- 

 culating blood of pregnant females, these being in a sense 

 foreign to the blood should increase the proteolytic capacity 

 of the blood against them. Investigation actually corrobor- 

 ated the assumption, it being possible to demonstrate by 

 optical means that serum from gravid females has the power 

 of inducing cleavage of a placental peptone (obtained by 

 partial hydrolysis of human placental tissue by sulphuric 

 acid), while the same power does not exist in the serum of 

 normal, non-gravid individuals. The chemical diagnosis of 

 pregnancy can be made, however, in much simpler manner, 

 by dialyzing the serum of the pregnant woman in which 

 bits of boiled placental tissue have been suspended against 

 water, and then testing the dialysate for material responding 

 to the biuret reaction. At the present time Abderhalden is 

 still engaged in so far perfecting the method that it may be 

 adapted to the requirements of medical practice. 55 



65 E. Abderhalden and M. Kiutsi, Zeitschr. f. physiol Chem., 77, 249, 1912; 

 E. Abderhalden, ibid., 81, 90, 1912. (Employment of triketohydrindenhydrate 

 as peptone reagent.) 



