Bacterial
species
and
types
can
be
identified
by
specific
antigen
antibody
reactions.
Antigens
are
substances
that
induce
the
production
of
antibodies
in
a
foreign
species.
Bacteria
and
bacterial
components
serve
as
excellent
antigens.
The
test
includes production
of
antibodies
in
an
animal
host
and
testing
of
the
antiserum
by
either
the
agglutination
or
precipitation
test.In
the
agglutination
test,
a
drop
of
the
culture
of
a
particular
bacterium
is
mixed
on
a
slide
with
the
anti-serum
of
an
individual
infected
by
it
and
examined
under
a
microscope.
If
clumping
occurs,
the
test
bacterium
is
considered
to
be
the
same-
or
closely
related
to
the
bacterium
used
as
the
antigen.
