ABDERHALDEN TEST 195 



which is surrounded by a porcelain white ring and outside of this a zone of inflam- 

 mation, shows a positive test. 



THE ABDERHALDEN REACTION 



According to Abderhalden, specific ferments of a protective nature 

 (abwehrfermente) appear in the circulation following parenteral injec- 

 tion of various materials and are different from ordinary antibodies. 



The substance which causes the production of these specific ferments 

 is called the substratum instead of antigen, the usual designation of 

 antibody stimulating substances. The principle of the test is that 

 when serum containing such specific ferments is placed in contact, in 

 vitro, with the substratum the latter is digested with the production of 

 soluble products, which can pass through a dialyzer and be recognized 

 in the dialysate. The special dialyzers are called thimbles and those 

 prepared by Schleicher and Schull are recommended. 



About 0.5 gram of the substratum is placed in a thimble, which has been intro- 

 duced into a clean Erlenmeyer flask and covered with 1.5 c.c. of the patient's serum. 



The thimble is then withdrawn, its open end closed by forceps, then thoroughly 

 washed with distilled water and again introduced into a clean Erlenmeyer flask 

 containing 20 c.c. of sterile distilled water. Toluol is then introduced into the 

 flask so as to cover the water around the thimble. These flasks are then put in 

 the incubator for eighteen hours and the dialysate tested for protein by the ninhydrin 

 test. For this one uses 0.2 c.c. of a i% solution of ninhydrin in water and adds 

 10 c.c. of dialysate and the mixture brought to a boil in a test-tube. A positive 

 reaction is a violet blue. 



The biuret reaction may also be used. 



The difficulties in the way of handling the thimbles and preparing the substratum 

 are so great that Abderhalden questions the competency of even experienced 

 serologists for the carrying out of the test. 



The main objection to the test, however, is that it is affected quanti- 

 tatively so that using varying amounts of reagents one may obtain 

 contradictory results; thus it is possible to obtain ninhydrin reactions 

 with the serum of a male animal acting upon a placental substratum. 



While the test is best known in connection with the recognition of 

 pregnancy it has also been employed for the diagnosis of malignant 

 tumors, etc. 



In taking serum for the test it is necessary to withdraw the blood as 

 long after a meal as possible, preferably in the morning before breakfast. 

 The blood is taken into paraffin-coated centrifuge tubes and most 

 thoroughly centrifuged, so that it is absolutely free from red cells. 

 It is pipetted off and kept on ice. 



