The Microscope

Question 1

What 2 lenses make a microscope a compound microscope?

Answer 1

Has objectives + eye piece

Question 2

Why can’t using our eye be enough to see small things?

Answer 2

Eyes don’t have enough resolving powers to distinguish between 2 small dots/objects

Question 3

What is the range of items that you’d be able to see with a light microscope?

Answer 3

1mm - 100nm

hair thickness to bacteria

Question 4

What is the range of items that you’d be able to see with an electron microscope?

Answer 4

10nm - 1micron

virus-atoms

Question 5

What are the 6 different microscope types?

Answer 5

1. Optical: uses light
2. x Ray microscope
3. Scanning Acoustic Microscope: uses sound waves
4. Scanning Helium Ion Microscope: uses atomic particles
5. Neutron Microscope: uses atomic particles
6. Electron Microscope: uses beams of electrons

Question 6

What kind of light does a light microscope use?

Answer 6

Visible light

-UV light incase of fluorescence

Question 7

How is thew light used in the light microscope?

Answer 7

Light is refracted with optical lenses

• first microscopes that were invented belong to this category
• -can be further subdivided

Question 8

What are we able to see through a compound microscope?

Answer 8

Biological specimens (dead or alive) are transparent to the light

Question 9

What is added to be able to see images through a compound microscope?

Answer 9

Optical Staining-changing light colour

Dyes- for different parts of cell

Question 10

What are the 5 optical staining methods?

Answer 10

Bright field 
Dark field
Phase contrast
Differential Interference Contrast (DIC) - 3D
Fluorescence

Question 11

What is a Stereo/Dissecting Microscope?

Answer 11

Looking at the surface of something

• true steriovision
• both lenses have their own optical path

Question 12

What can be viewed through a dissecting microscope?

Answer 12

Live+dead specimens

-just looking at it with the light

Question 13

What is a confocal microscope?

Answer 13

Takes many infocused pics of the sample at different levels. The computer reconstructs the full image so that all the individual pictures are stacked to create a focused image
-dye used

Question 14

What is an electron microscope?

Answer 14

Does not use glass lenses and uses electrons and electromagnets to focus the image

Question 15

Why are electrons good for microscope imaging?

Answer 15

Electrons have short wavelengths which produce a very clear image

Question 16

When using the electron microscope, what stain is used?

Answer 16

Specimen has to be stained with metal because electrons can pass through regular dye

Question 17

How do you prepare the sample for microscope use?

Answer 17

If not alive, need to preserve it as close to life as possible = fixing the sample

Question 18

What is a scanning electron microscope?

Answer 18

Produces 3D images

Question 19

What 2 microscopes can only produce black and white images?

Answer 19

Transmission and Scanning electron microscopes

-colour can be added additionally later

Question 20

Which microscope uses fluoresces ?

Answer 20

Confocal

-expensive