Dark
Field
Light
Microscopy
In
this
case,
a
dark
background
is
established,
and
only
the
object
is
illuminated.
A
special
condenser
scatters
the
light
and
causes
the
light
to
hit
the
object
from
different
directions.
Some
light
is
reflected
from
the
object
into
the
lens,
and
the
object
is
seen
clearly,
but
since
there
is
no
direct
background
light,
the
surrounding
area
appears
dark
This microscopy is
important
in
the
diagnoses
of
certain
diseases
when
small
live
organisms
near
the
limit
of
resolution
of
the
microscope
must
be
observed.
For
example,
the
syphilis
spirochete,
Treponema
pallidum
may
be
seen
in
scrapings
taken
from
a
skin
lesion.
Since
stain
is
not
used,
the
organisms
may
be
seen
moving
about
with
a
characteristic
rotary
motion.
