Transcript The Microscope

The Microscope
The Unseen World
The Penny
The Penny
VDB
Victor D. Brenner
Frank Gasparro
The Microscope!!
Is an instrument which provides an enlarged
image of an object.
History
• Anton Von Leeuwenhoek 1632
• First to observe living bacteria
& drew them.
• Also looked at sperm & blood
Ash Tree cross- section
The Universality of Sex (sperm)
Three shapes of bacteria
• Robert Hooke (1665)
• Examines cork.
• First to use the term
“cell” referring to the
many little boxes in
cork.
Light Microscopes
The type we use in our labs
•
Most commonly used
microscope
–
Uses light and lenses to magnify &
view the specimen
–
Has two sets of lenses – Ocular (eye
piece) & Objective (near the object
being viewed)
–
Total magnification on our scopes =
40 – 1000 times
–
Total magnification = Ocular (10X) x
Objective (40X
•
Low: 4 x 10 = 40
•
Med: 10 x 10 = 100
•
High: 40 x 10 = 400
Ocular – Eye piece (magnifies 10X)
Neck – Supports the eyepiece.
Objectives – 4 – 100x magnification
Arm – Supports neck and objectives. Carry by
this
Stage and clips – Holds slides in place
Adjustments – Coarse & Fine. Focuses image
Diaphragm – Controls the amount of light
coming through the stage
Light – Electric light source
Base – Bottom of scope. One hand goes
underneath
The Diaphragm
• Use the Diaphragm to
adjust the amount of
light
Focusing
Use the Adjustment
knobs to focus the
image
• Coarse adjustment
brings the image into
near focus
• Fine adjustment
(smaller knob) brings it
into fine focus.
– Only use this one when
on you are on high
power
Rules for using the Microscope
1.
2.
3.
4.
5.
6.
7.
8.
Use only the assigned microscope
Carry & place the scope properly (6cm from edge of table)
Do not let the cords dangle or get into the sinks
Clean lens only with lens paper. NO FINGERS!
Start on low (4x) power when you start your observations
Always focus (move the stage) away from the slide
Use the coarse adjustment first then the fine adjustment
Be careful when switching to high (40x) power to se that there is enough
clearance between the objective and the slide
9. Do not use the coarse adjustment knob on high (40x) power
10.When you are done with the scope, turn off the light switch
11.Return the low power objective (4X) into place and raise the stage all the
way up.
12. Always put scope away with cord wrapped around it, cover on & the low
power objective in place
13.Put scopes away with the numbers facing out into the proper slot
14.Clean and dry all slides and cover slips before putting them away
Compound Microscope images
Diatom
Amoeba
Paramecium
Hydra budding
Euglena
Daphnia
Electron Microscopes
Uses electromagnets and
streams of electrons
to view a specimen
200,000 – 1,000,000x
magnification
Animal cell
Plant cell
Transmission Electron Microscope (TEM) 1931
Image is seen on a computer screen
•
•
•
Specimen must be thinly sliced and coated with metal.
Gives a 2D image of specimen
Specimen must be dead
Herpes simplex viruses
Staphylococcus aureus
These have all had color added to them!!!
E. coli bacteria
Scanning Electron Microscope
(SEM) – 1935
1. Gives a 3D image
Hookworm mouth!!!!!!
Images
Weevil
Tick
Diatom
Radiolarian
Threads
100x
The Letter “e”
40x
400x
Making a Wet Mount Slide
• 1. Get a thin slice/piece of whatever your specimen is.
• 2. Place ONE drop of water directly over the specimen.
• 3. Place the coverslip at a 45 degree angle (approximately), with one
edge touching the water drop, and let go.
Beware of Air Bubbles!!