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The MicroscopeThe 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
Three shapes of bacteria
The Universality of Sex (sperm)
• 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 high power
Rules for using the Microscope1. Use only the assigned microscope2. Carry & place the scope properly (6cm from edge of table)3. Do not let the cords dangle or get into the sinks4. Clean lens only with lens paper. NO FINGERS!5. Start on low (4x) power when you start your observations6. Always focus (move the stage) away from the slide7. Use the coarse adjustment first then the fine adjustment8. Be careful when switching to high (40x) power to se that there is enough
clearance between the objective and the slide9. Do not use the coarse adjustment knob on high (40x) power10.When you are done with the scope, turn off the light switch11.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 place13.Put scopes away with the numbers facing out into the proper slot14.Clean and dry all slides and cover slips before putting them away
Compound Microscope images
Paramecium
Euglena
Daphnia
Amoeba
Diatom
Hydra budding
Electron MicroscopesUses electromagnets and
streams of electrons to view a specimen
200,000 – 1,000,000x magnification
Plant cell
Animal cell
Transmission Electron Microscope (TEM) 1931Image 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
Staphylococcus aureus
E. coli bacteria
Herpes simplex viruses
These have all had color added to them!!!
Scanning Electron Microscope (SEM
) – 19351. Gives a 3D image
Hookworm mouth!!!!!!
Images
Weevil
Radiolarian
Diatom
Tick
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.
The Letter “e”
40x 400x
Beware of Air Bubbles!!