Americus times-recorder. [volume] (Americus, Ga.) 1891-current, 1916-06-13
NEW NJ { 7 HO D
Of PREPAR|N c
CHOLERA SERUM

new method of preparing anti-hog-
cnolera serum which permits the
economical production of clear ster-
llized product, has just been described
in the Journal of Agricultural Re-
search of the U. S. Department of Ag-
riculture. The advantage claimed for
the new method is that it makes pos
sible the production of an anti-hog-
cholera serum which can be quickly
sterlized by heat to a point that will
absolutely kill any germs OF foot-and-
mouth disease and so yield a serum
that is absolutely safe even it taken
from hog which might harbor foot
and-mouth, disease and yet give no in
u}ication of being infected
The method, as described by its dis
coverers, DR.. Marion Dorset and R. R.
Henley, of the Biochemic Division, Bu-
reau of Animal Isdustry, consists in
adding slight amount of an extract
from ordinary white navy beans to the
defibrinated hog g-cholera-immune blood
which has been the form OF the serum
used In the past. The addition of this
bean extract causes the red cells of the
blood to glutinate and when the mix
ture is whirled on centrifuge the red
cells pack together and form rather
stiff jelly-like mass. 1t is then possi-
bic to pour off clear serum, leaving
behind the red cells which play no
part in preventing hog cholera and
which in fact simply tend to dilute the
serum and render its sterilization by
heat impracticable. To increase the
yield of clear serum the discoverers
added small amount of ordinary
selt and found that they obtained
frcm 70 to IA per cent. of clear serum
The clear serum thus obtained it was
found could be heated for so minutes
at a temperature of 60 degrees Cent?
grade without changing it's consist
ency or lessening in any way it's eff
fectiveness in preventing hog chol-
era. The heating to this point for
this time is more than sufficient to
kill any germ of foot-and-mouth dis
ease which might accidentally be
present. Practical tests with hogs
show that probably all of the anti
bodies useful in combating hog chol-
era were retained in the serum and
the red cells extracted contained so
few, if any, Of these valuable bodies
as to make the residue of red cells
Useless in preventing the disease.
Beofre the clear serum was develop
ed. many attempts were made to ster-
ajize by heat in practicable way the
ordinary defbrinated blood. 1t was
found. however, that heating the old
product up to so degrees Centigrade
resulted in more or less complete
:&gulat;Jn of the defibrinated blood
nd in the destruction of the serum so
concerned. 1t was found that the
highest temperature that could be
used was so degrees Centigrade and
it was necessary to keep the old ser
um at this temperature for l hours to
make certain that the virus of foot
a, d-mouth disease was killed Heat
ing serum at steady temperature
over this long period in ordinary prac-
tice is difficult and too expensive.
Attempts also were made to make
A cellar serum by centrifugalizing. 1t
was found, however, that while the
csntifuge would separate to some ex-
tent the red cells, they were in such
shape that it was difficult to separ-
ate the serum completely. An import
ant quantity of antibodies were left
behind in the red clot, and the result
Ing product was a cloudy rather than
clear serum. With this process,
moreover, it was possible ordinarily