MICROSCOPE USE AND MAINTENANCE(REVISED and CURRENT).ppt

Microscopy notes for medical laboratory students

1. MICROSCOPE
Use, Care and Maintenance
Microscope Use, Care and Maintenance MDC 2011
Artist: Scott Weichert

2. Learning objectives
Know various parts of a microscope
and their functions.
Know working principle of a
microscope.
Know proper use of a microscope.
Know maintenance procedures
applicable to a microscope.
Know installation requirements
Microscope Use, Care and Maintenance MDC 2011

3. Definition of a Microscope
An optical instrument that augments the
power of the eye to see small objects.
The name microscope was coined by
Johannes Faber (1574-1629) who in 1628
borrowed from the Greek to combine micro-
small with skopein-to view.
Common microscope in use is a compound
microscope.
Microscope Use, Care and Maintenance MDC 2011

4. Compound Light Microscope
uses a combination of lenses
as opposed to simple
microscope which uses one.
Can use either natural light
(Mirror) or 12V battery or
electrical power.
Compound microscope can
either be monocular,
binocular.
Microscope Use, Care and Maintenance MDC 2011

5. Working Principle of a Compound Microscope
Microscope Use, Care and Maintenance MDC 2011

6. Parts of a Microscope
Microscope Use, Care and Maintenance MDC 2011

7. Function of Microscope Parts
Eye piece–also called ‘ocular’ gives the
secondary magnification of the image
formed by the objective. Magnification
ranges form 5 –10X.
Body tube–contains mirrors and prisms
which direct image to the ocular lenses
Nose piece–is for holding, rotating and
aligning the objectives into position when in
use.
Objective–contains lenses which form
primary magnification of the object.
Common power of objectives are 4x,
10x,40x and 100x which requires immersion
oil when in use.
Microscope Use, Care and Maintenance MDC 2011

8. Color code bands of objective
lens
The color band is a quick reference to the goal
magnification.
One can swap to a certain goal magnification by
the color code, which may vary from region to
region.
Always check the color coding of each
microscope you purchase ,the common ones are:
-4x Red
-10x Yellow
-40x Light Blue
-100x White/black

9. Color code cont.
Other information on the objective lenses
include
-Magnification
-Medium
-Manufacturer
-Numerical aperture

10. Function of microscope Parts
Body –provides the frame work on which
the major parts are fitted.
Mechanical stage–is the platform on
which the object to be viewed is placed and
secured by mechanical clips. Light reaches
the specimen through an aperture
underneath. Has an adjusted knob for
moving the object.
Diopter adjustment ring-this compensates
for the difference in eyesight between your
eyes. Located on left ocular.

11. Function of Microscope Parts
Coarse adjustment–is for moving the
stage rapidly up and down. Should only be
used with the low or intermediate objectives
in place, never with the high power
objectives.
Fine adjustment-is used for obtaining
sharp image of the object in focus.
Pre focusing knob-controls the mechanism
for preventing collision between specimen
and objective
Microscope Use, Care and Maintenance MDC 2011

12. Function of Microscope Parts
condenser–is located below the
stage and contains lenses which focus
light from the light source to object
placed on the mechanical stage for
viewing. Can be raised or lowered by
the adjustment knob.
Iris diaphragm ring–is a mechanical
lever at the side of the condenser that
regulates size of the diaphragm thus
the amount of light that reaches the
condenser. Can be adjusted to
balance contrast, resolution and
brightness

13. Function of Microscope parts
Rheostat–regulates the amount of
light that originates from the light
source.
Light source–also called ‘illuminator’
provides light through the optical
components that is used to illuminate
the object.
Foot/base–is a flat surface that
provides overall support and stability to
the microscope

14. Installation requirements
Install the microscope on a sturdy,
level bench in a dust and dump free
room
It should be away from vibrators, i.e
centrifuge, refrigerators etc
Convenient table height or adjustable
stool
Away from water sink and chemicals

15. Setting up Illumination
1.Place specimen on the stage. Use coarse
adjustment and 10X objective to focus the
specimen.
2.Completely open the iris diaphragm and raise
the stage to the point where the field is
brightest.
3.Remove the eyepiece, look down the tube and
adjust the light at the source until the objective
lens is fully illuminated.
4.Replace the eyepiece, close the iris diaphragm
until the aperture of the objective is 2/3 visible
to give maximum resolution.
5.Replace the eyepiece and do the same with
other objectives.
Microscope Use, Care and Maintenance MDC 2011

16. Using Oil Immersion Objective
100x oil immersion objective is the most
powerful objective of light microscope
1.Use coarse adjustment to rack up the
stage.
2.Place the slide on the stage with the
blood film uppermost.
3.Place 1 -2 drops of oil immersion on the
smear to be examined.
4.Carefully lower the 100x objective until
the lens is in contact with the oil
immersion.
Microscope Use, Care and Maintenance MDC 2011

17. Cont.
5.Use fine adjustment to obtain a sharp
image while balancing illumination with
iris diaphragm.
NB: Oil immersion is used to reduce
scattering of light transmitted and to
increase resolution. It must have same
optical properties as the glass used for
lenses i.e. refractive index of 1.515.

18. Handling Procedures
Clean the lenses after use with
lens cleaning tissue and lens
cleaning fluid. Others options
include muslin cloth and silk.
Never use Kimtex, Kimwipes,
tissue paper or hand towels.
Never use xylene or any
corrosive solvent to clean the
lenses.
Microscope Use, Care and Maintenance MDC 2011

19. Always remove oil from the
objectives , stage, condenser
and diaphragm using lens
cleaning tissue and cleaning
fluid
Prevent immersion oil contact
with other objectives other than
100x
Never touch the optical lenses
with bear hands since this
leaves finger marks that will
cause confusion during
microscopy.
Handling Procedures
Microscope Use, Care and Maintenance MDC 2011

20. Handling procedures
Always keep eye pieces in place to
protect inner surfaces.
Avoid dust collection and oil immersion
on objectives and eyepieces, which
may lead to growth of fungus.

21. Rotate the nose piece to
ensure that the lowest
magnification objective remains
in position at the end of each
day.
Always cover the microscope to
keep it away from dust when
not in use.
For long storage keep in air
tight bag with 100g drying
agent e.g silica gel or dry rice.
Handling Procedures
Microscope Use, Care and Maintenance MDC 2011

22. The right way of carrying a
microscope. Always hold the
base and the arm as shown.
The wrong way of carrying a
microscope.
Handling Procedures
Microscope Use, Care and Maintenance MDC 2011

23. Replace bulbs and
fuses as required and
always have enough in
store as back up.
Handling Procedures
Microscope Use, Care and Maintenance MDC 2011

24. Trouble shooting
If the bulb doesn’t light check if there is
power supply, bulb is blown off or not,
rheostat is turned on etc.
If a slide is put on stage and the image
can not be viewed, check if probably
the slide was placed upside down, no
oil immersion was put on the slide or
wrong objective being used.
Microscope Use, Care and Maintenance MDC 2011

25. Trouble shooting
If the stage is wobbling then it needs
tightening.
If the fine and coarse adjustments are loose
then be tightened since the stage will not
move up and down as required.
Always call an expert to service your scope
in case of any problem. This should always
be done as soon as detected
Microscope Use, Care and Maintenance MDC 2011

26. Trouble shooting
If the objectives are worn out then the
images obtained will be blurred and
won’t allow accurate judgments to be
made. Replace as necessary.
If black dots appear on the lenses they
may be on the eyepiece or slide,so if
they move when the eyepiece is
rotated,this means the dust is on the
eyepiece.

27. Trouble shooting cont.
If the black dot moves when the slide
moves, it is present on the slide
Always have a back up microscope
incase of problems.
NB. Most of the above common problems
can be prevented by routine cleaning
and maintenance, however always seek
professional service for problems you
cannot handle as detected or planned,
annually or bi-annually.

28. Check all optics for damage.
Check coarse and fine adjustments if
appropriate.
Dust clean external surfaces of a
microscope.
Roll down the stage away from the
objectives when you are done.
Never drag a microscope when moving it.
Daily Maintenance
Microscope Use, Care and Maintenance MDC 2011

29. Microscope Maintenance Chart
All the above maintenance activities when done must be logged in the
microscope maintenance sheet shown above
IF IT IS NOT DOCUMENTED,IT HAS NOT BEEN DONE.
Microscope Use, Care and Maintenance MDC 2011

30. Logs
It is good practice to maintain a log
book for:
-problems encountered
-routine maintenance
-repairs
-spares

31. References
Basic malaria microscopy. Part 1.
Learners guide.
Bench Aid for the diagnosis of malaria
infections. Second Edition.
Use of light microscopes. Department
of Biology, Bates College 2002.
Microscope Use, Care and Maintenance MDC 2011

32. THANK YOU