Download 100x(white) (oil objective lens)

Microscope: instrument that magnifies small
objects that cannot be seen by naked eye.
* Microscope can be divided into 2 kinds:
-simple microscope : consist of one lens
(ocular lens)
- compound microscope: consist of 2 lens
(ocular +compound lens) (light
microscope+electron microscope)
*Light microscope can be divided into:
bright field\dark field\phase contract
\fluorescent microscope
*Part of microscope:
1- ocular lens(eye piece): first lens
element in microscope , it will show the
final image
2- body tube : connect the objective lens
with ocular lens
3- rotating nosepiece: carry the objective
lens
4- objective lens: magnify the specimen
5- stage: support the slide
6- mechanical stage: move the slide
horizontally and vertically
7- condenser: focus the light onto the
specimen+control the amount of light
8- iris diaphragm: control the amount of
light
9- coarse adjustment: get the picture out
10- fine adjustment: make the picture clear
* Lenses and total magnification:
- the magnification of the specimen depend
on two lens system in light microscope:
1) ocular lense
2) objective lens
- ocular lens magnify the specimen 10x
- objective lens can be divided according to
their magnification power into :
4x(red)
10x(yellow)
40x(blue)
100x(white)
(oil objective lens)
-what is the use of oil?
(why?)
*Total magnification =
mag. of ocular lens x mag. Of
objective lens
*Working distance: distance between the
objective lens and the slide
- as the objective lens power increase
the working distance decrease
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1) bright field microscope:
- Source of illumination is light
- The specimen must be stained
- We can see shape ,arrangement, size ,
color of m.o
- We cannot see viruses
- Specimen darker than background
2) Phase contrast:
-Widely used to view the unstained living
specimen by increasing the contrast
between the object and background
,and this happen according to special
condensers
-No need to stain the specimen
-Specimen darker than background
3) Dark field microscope:
-Different from bright field or phase
contrast microscope
- Use special condenser with blocking disk
- No light will pass into the objective lens if
there is no specimen on the stage
-Objects or particle on the stage
will
reflect the light into the
objective lens
and appear as bright
object on a black
background
- No need to stain the specimen
4) Fluorescent microscope:
- the specimen must be stained with
fluorescent dye
- source of illumination is u.v light
* Electron microscope:
- Source of illumination is beam of electron
- We can see viruses
- 2 kind of electron microscope:
1) scanning E.M:
look at the surface of bulk object by
scanning the surface with fine electron
beam and measuring the reflection
2) Transmission E.M:
- Passes electrons completely through
sample
- It can obtain detailed information of the
sample