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

Threads

100x

Beware of Air Bubbles!!