SERUM DIAGNOSIS OF ROUS'S CHICKEN SARCOMA, 

 BASED ON CHEMICAL METHODS 



CASIMIR FUNK 



Introduction. Serum diagnosis o£ tumors is, at present, in a 

 preliminary stage. During the last few years there have been de- 

 scribed several methods which are mostly based on biological prop- 

 erties of serum. None of these methods, however, has given satis- 

 factory results. Among the procedures tried by the author were 

 the method of Freund, the meiostagmin-reaction of Ascoli, and the 

 optical method of Abderhalden. In view of the failure of these 

 biological tests to give a reliable method for tumor diagnosis, it 

 seemed advisable to ascertain whether purely chemical methods 

 would serve better for this purpose. 



This investigation was conducted with serum of chickens inocu- 

 lated with Rous's chicken sarcoma. The large amount of serum 

 obtainable from these animals was a great advantage for our pre- 

 liminary studies. The tumor used being very malignant, the animals 

 died in a few weeks. One would therefore expect the chemical 

 changes to have been very pronounced. In the first part of the work, 

 the serum was precipitated with absolute alcohol ; and the amount of 

 precipitate, and its nitrogen and phosphorus contents, were estimated. 

 The filtrate was analyzed in the same way. Throughout the whole 

 inquiry, normal and tumor sera were treated simultaneously. The 

 results tend to show that the tumor serum was poorer in proteins 

 and phosphorus. 



Better results were obtained by analyzing serum itself. In this 

 case the proportions of nitrogen, phosphorus, sulfur, chlorin, amino- 

 nitrogen, and sugar, and the molecular depression, were taken into 

 account. Of 22 tumor sera, 20 gave practically identical results. 

 Tumor serum was, as a rule, poorer in nitrogen, phosphorus and 

 sulfur than normal, though richer in amino-nitrogen ; the molecular 

 depression was greater in normal serum. Sugar was determined 

 in serum which had been kept, for some time, in an incubator; 



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