The Sunday telegram. [volume] (Clarksburg, W. Va.) 1914-1927, 1916-06-18
New Method.

A New method of preparing ant-hog-cholera serum, which
permits the economical production of a clear sterilzed product
has Just been described in the Journal of Agricultural Research
OF the Cnited States Department of Agriculture. The advantage
claimed for the new method is that it makes possible the produc-
non 81 an antl-hog-choera serum which can be quickly sterilized
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
II taken from a hog which might harbor foot and mouth diseases
and yet give no indication of being infected.
The method, as described by it's discoveries DIR Marion Dor-
set and R. R. Henley, of the Biochemic division. bureau of animal
industry consists in adding a slight amount of an extract from
Ordinary %hlte navy beans to the ~defbrinared hog-cholera-im-
mune blood, which has been the form of the serum used in the past
Inc addition OF this bean extract causes the red cells of the blood
~ ~ "sEi i ana when the mixture is whirled on a centrifuge
the red cells pack together and form a rather stiff ielyJike mass
- - oon Ten pos POSSIBLE 10 pour oil a clear serum, leaving behind the
in fact simply tend to dilute the serum and render its sterilization
by heat lmpraGticable. To increase the yield of clear serum the
they obtained from seventy to seventy-four per cent of clear ser.
for thirty minutes at a temperature of sixty degrees Centigrade
without changing its consistency or lessening in any way its effec-
this time is more than sufficient to kill any germs of foot-and.
mouth disease, which might accidentally be present. Practical
tests with hogs show that probably all of the antibodies useful in
combating hog cholera were retained in the serum and the red
cells extracted contained so few. if anv If tboso ra,raSi, N Ls j reu
as TO make the residue of red cells useless in preventing the dis,
ease. N N
Before the clear serum was developed. MANY attemnts woro
made to sterihze by heat in a practicable way the ordinary defbri-I
mated blood. 1t was found, however, that heating the old product
up to sixty degrees Centigrade resulted in more or less ca pTIat
coagulation of the defbrinated blood and in the destruction Of the
serum so far as its commercial worth is concerned. 1t was found
that the highest temperature that could be used was 6ftv J J. 9
Centigrade and it was necessary to keep the old serum at this
temperature FOR twelve hours to make certain that the viris of
foot-and-mOuth disease was killed. Heating serum at a steady
temperature over this long period in ordinary practice is difficult
and too expensive.
Attempts also were made to make a clear serum by centrifu-
galzlng. 1t was found, however, that while the centrifuge would
separate to some extent the red cells, they were in such shape that
II was difficult to separate the serum completely. An important
quantity of ~anti-bodies were left behind in the red cIot. and the
resulting product was a cloudy rather than a clear serum.
With this process, moreover, it was possible ordinarily to-
secure only about fifty per cent of serum. Under the new method
1t is possible to secure as high as seventy-four per cent of clear
serum, which in actual test has proved to be fully potent. This
clear serum, moreover, can be completely steriiized in thirty min
utes, whereas the old serum had to be heated steadily for twelve
hours.
The new form of serum, as far as the department knows is
not vet being made or put on sale by the commercial serum Iabora-
tories. AS this process was discovered by the federal government
anyone in the United States is free to use it.