the uses and its working principle

1. Bright field microscope
-by kavimugaraja

2. IMPORTANCE OF THE MICROSCOPE
 Importance for haemotology
 Microbiology
 TB
 malarial testing

3. ADVANTAGES
 It is very simple to use with fewer adjustments
needed to be made to view specimens.
 Some specimens can be viewed without staining.
 They don’t alter the color of the specimen.
 It is versatile and adaptable to the situation

4. Disadvantages
 Greater contrast adds distortion(employing an iris
diaphragm will compensate this problem).
 This microscope can”t be used to view living
bacteria
 This method needs a strong light source for high
magnification applications and intense lighting can
produce heat that will damage specimens or kil
living microorganisms

5. Terminologies
 RESOLUTION:
Ability to distinguish(resolve)two close
together points as separate.
 CONTRAST:
differences in intensity between two
objects,or between an object and background
 Important in determining resolution
 Staining increases contrast.

6. DESCRIPTION
 Brightfield microscopy
it is the most simple form of
microscopic illumination techniques and is generally
used with compound microscope.
the name “brightfield” is used because of that the
specimen is dark and the background is bright
viewing field simple light microscopes as referred to
as brightfield microscopes.

7. SPECIMEN THAT CAN BE OBSERVED
 Naturally pigmented or stained specimens are best
suited to view
 Living specimens of bacteria are useless because
it need high contrast to view and it may kill the
specimen
 Non photosynthetic protists and metazoans also
cannot be viewed

8. Working procedures
 The specimen is placed on the stage of microscope
and incandescent light from the light source is
aimed at the lens(condenser).
 The condenser focus the light on the specimen and
later the light is collected by objective lens
 The objective lens magnifies the light and pass it to
the eyepiece.
 This bright field microscope use critical or kohler
illumination

9. Bright field microscope working

10. Thank you