PATHOLOGY: W. N. BERG 
261 
THE TRANSFORMATION OF PSEUDOGLOBULIN INTO EUGLOBULIN 
By William N. Berg 
PATHOLOGICAL DIVISION; BUREAU OF ANIMAL INDUSTRY. WASHINGTON, D. C. 
Communicated by R. Pearl, February 16, 1917 
In several publications Banzhaf^ states that when diphtheria serum 
is heated as it is in the preparation of antitoxin, part of the pseudo- 
globulin is transformed into euglobulin. Details regarding the methods 
of analysis, or the analytic data on which Banzhaf based his conclusion 
were not found in the publications examined. 
This transformation has both a practical and a theoretical interest. 
It facilitates the concentration of the antitoxin present in the serum by- 
removing protein without removing antitoxin, so that the final product 
contains all the antitoxin associated with much less protein. This is 
desirable because certain of the serum proteins have very little therapeutic 
value. In applying the heat treatment for the first time to a serum 
such as anthrax serum, for example, it is obviously desirable to be 
certain that a similar transformation takes place. Otherwise there 
would be no need of the heat treatment, and besides, the heating may 
cause loss of potency. 
On the theoretical side, the fact that pseudoglobuHn can be trans- 
formed into euglobulin without affecting the total number of antitoxic 
units is almost conclusive proof that the antitoxin is a substance sep- 
arate from pseudoglobulin. That this transformation may take place 
in some sera, but not in all, is indicated by the following experiments, 
in which the heating of the serum was carried out under carefully con- 
trolled conditions and the analytic data obtained by improved methods. 
In all, four horse sera were used, which will be designated as follows: 
Anthrax 48. The serum obtained from Horse 48; used in a previous 
work.2 Potency high. 
Anthrax 96. The senun obtained from Horse 96; used in a previous 
work. Potency lower than Serum 48. 
Diphtheria 1. A mixture of sera obtained from 2 horses. Potency 
high. 
Tetanus 1. A mixture of sera obtained from 2 horses. Potency fair. 
The first attempts to detect the transformation failed almost certainly 
because the experiments were made in connection with the prepara- 
tion of globulin for therapeutic use. Better analytic results were ob- 
tained when using smaller amounts of serum under conditions adapted 
to quantitative analysis and separate from antitoxin preparation. 
Heating the serum. — The procedure with a single serum was as follows. 
