Accu-Scope 3000-LED series User manual

INSTRUCTIONS
73 Mall Drive, Commack, NY 11725 • 631-864-1000 (P) • 631-543-8900 (F)
www.accu-scope.com • [email protected]
3000-LED
SLIDER PHASE CONTRAST MICROSCOPY
INSTRUCTIONS
PHASE ANNULI
ARE PRE-CENTERED

3000-LED SLIDER PHASE CONTRAST INSTRUCTIONS
Slider Phase Contrast
Installation & Use Instructions
Phase contrast should be used for
observing unstained specimens (i.e.
cultured cells) at high contrast.
Prior to shipment your phase contrast set
was assembled, tested and inspected at
our distribution center in New York. The
phase slider objectives and condenser
were pre-centered and aligned by our
technicians.
IMPORTANT: Before you can use the
phase slider, you must remove the
dust shield cover from the condenser
housing and install the phase annuli
slider in its place. (See FIG. 1)
IMPORTANT: The condenser has
been intentionally installed in a slightly
rotated orientation. This was done to
prevent accidental contact on the
stage control arm when using the
annuli slider.
In the event the condenser is
removed, it MUST BE REINSTALLED
in the original orientation.
The REFERENCE LINE on the
condenser must be ALIGNED WITH
THE SET SCREW in the condenser
holder.
Objectives
Green Filter
Phase Slider

3000-LED SLIDER PHASE CONTRAST INSTRUCTIONS
REMOVING THE
DUST SHIELD COVER
Slide the dust shield cover out from the condenser housing
(FIG. 1). Be sure to keep it to reinstall it should you need to
transport the microscope. FIG. 2 shows the condenser
housing with the dust shield cover removed.
INSTALLING THE
PHASE SLIDER
Before inserting the Phase slider, it is recommended the iris
diaphragm lever be set to PH on the condenser.
Insert the slider into the slot on the condenser as shown in
FIG. 3 & FIG 4.
Move the slider to its position that corresponds to the phase
objective in use (i.e., 40x objective = 40x position on slider).
IMPORTANT!
Raise the condenser to its uppermost position.
Refer to the instruction manual provided with the microscope
on how to focus on a specimen.
FIG. 1
FIG. 2
GREEN FILTER
The included green filter can be mounted on top of the
illuminator housing.
FIG. 3
FIG. 4
Condenser Height Adjustment Knob

3000-LED SLIDER PHASE CONTRAST INSTRUCTIONS
PHASE CONTRAST
MICROSCOPE
The normal microscopic object is seen
because it has regions of varying density. In
normal brightfield illumination a completely
transparent specimen is very difficult to
observe in detail because all areas of the
specimen are equally dense. Darkfield
illumination displays border effects in
completely transparent specimens due to
edge scattering and diffraction of light.
Polarized light is useful when transparent
specimens have directional or crystalline
properties.
Phase contrast microscopy is a type of
illumination system to observe transparent
media. This form of illumination is utilized
extensively in the study of transparent living
cells without the need for staining or fixing
while being able to obtain good image
contrast. The light from phase contrast
illumination arrives at the user’s eyes at ½
the normal wavelength. This light altering
system produces a visible image of an
otherwise invisible, transparent specimen.
The optical light path necessary for phase
contrast is shown in Figure 1. A clear annulus
in the focal plane of the condenser is imaged
at infinity by the condenser and then re-
imaged by the objective in its rear focal
plane. The undiffracted light passes through
this image. It is reduced in intensity and given
a one-quarter wave phase shift by means of
an annular phase pattern in the rear focal
plane of the objective. These two changes in
the undiffracted portion of the beam simulate
the phase and intensity distribution which
would be present in the objective focal plane
if the specimen had density variations rather
than refractive index variations. As a result,
the image formed by the beam interfering
with the diffracted beam simulates that of a
specimen having density variations.
IMAGE FORMATION
BY PHASE CONTRAST
An annular aperture in the diaphragm placed in the focal
plane of the substage condenser controls the illumination
of the specimen. The aperture is imaged by the
condenser and objective at the rear focal plane or at the
exit pupil of the objective. A phase shifting element, or
phase plate, is placed in the image plane. Light passing
through the phase altering pattern acquires a ¼ wave
length advance over that diffracted by the object structure
and passes through that region of the phase plate not
covered by the altering pattern. The resultant interference
effects of the two portions of light form the final image.
Altered phase relations in the illumination rays, induced
by otherwise invisible elements in the specimen, are
translated into brightness differences by the phase
altering plate.

TROUBLESHOOTING GUIDE
PHASE CONTRAST MICROSCOPY
PROBLEM
CAUSE
CORRECTIVE MEASURE
Poor phase
contrast image
is obtained
The condenser phase annulus image
and the objective phase plate are not
aligned
Adjust the phase annulus so that it is
aligned with the objective phase
plate.
The condenser phase annulus and the
objective phase code do not match.
Rotate the phase annulus selector
wheel to the position that matches the
objective in use
The phase difference of the specimen
is too large.
Prepare the specimen using a
different refractive index immersion
fluid
The specimen cover glass is incorrect
Replace with 0.17mm thick cover
glass