CONCENTRATION OF SYMPTOMATIC ANTHRAX 
(BLACKLEG) TOXIN 
[PRELIMINARY PAPER] 
By Wiixiam N. Berg 
Biological Chemist, Pathological Division, Bureau of Animal Industry , United States 
Department of Agriculture 
Following is a preliminary report on some experiments made for the 
purpose of devising a practical method for concentrating the toxin de¬ 
scribed by Kelser in the preceding paper. When received for concen¬ 
tration this toxin was a liquid obtained by filtering blackleg cultures 
through Berkefeld filters. Four cc. or more of this filtrate was a fatal 
dose for 350-gm. guinea pigs, killing within 48 hours when the dose was 
small(4-5 cc.) and in an hour if the dose was large (10 cc.). All of the 
toxicity tests in this report involve the intramuscular injection of the 
toxin or its concentrate into the leg of the experimental animal. 
At first an attempt was made to precipitate the toxin with (1) alcohol, 
(2) half-saturation with ammonium sulphate, (3) saturation with am¬ 
monium sulphate, or (4) zinc chlorid. In general the chemical methods 
for the purification of tetanus toxin devised by Brieger and Boer 1 and 
by Hayashi 2 were followed, but without success. The precipitates ob¬ 
tained were not toxic to guinea pigs; the details of the chemical work 
will, therefore, be omitted. Foth 3 states ( p . ro, 21) that the toxin can 
be precipitated out of a germ-free filtrate by an excess of absolute alcohol. 
Grassberger and Schattenfroh 4 in their monograph state that nontoxic 
products are obtained by drying the toxin in vacuo at 30° C. (p. 21) or 
by precipitation with ammonium sulphate or alcohol (p. 24 ). 
The following method of drying the toxin to a paste which resembles 
the ordinary beef extract was successful on a laboratory scale. Experi¬ 
ments on large scale drying and on the keeping qualities of this product 
are under way. This method of drying has been applied by various in¬ 
vestigators to the drying of meat, milk, and cultures. Among the first 
1 Brieger, L., and Boer. UEber antitoxine end Toxine. In Ztschr. Hyg. u. Infektionskrank., 
Bd. 31, Heft 2, p. 259-268. 1896. 
- UEBER DIE TOXINE DER DIPTHERIE tJND DES TETANUS. In Deut. Med. Wchnschr., Bd. 
*2, No. 49, p. 783"78 s* i ^96* 
1 Hayashi, H. weitere forschungen uber die chemische natur des tetanus-toxins. In Arch. 
Expt. Path. u. Pharmakol., Bd. 47, Heft 1/2, p. 9-18. 1901. 
* Foth, H. neue rauschbrandimpfstoffe. In Ztschr. Infektionskrank. Haustiere, Bd. io, Heft 1, 
p. 1-22. 1911. 
1 Grassberger, R., and Schattenfroh, A. ueber das rauschbrandgift und ein antitoxisches 
serum. Iio p. Leipzig und Wien, 1904. 
Journal of Agricultural Research, 
Washington, I). C. 
or 
Vol. XIV, No. 6 
August 5, 1918 
Key No. A-41 
64611°—18-5 
(263) 
