Using A Microscope

Question 1

How do you prepare a dry mount microscope slide?

Answer 1

-take a thin slice of the specimen so that enough light is able to pass through it
-use tweezers to pick up the specimen and put it in the middle of a clean slide
-pop a cover slip of thin glass over the top

Question 2

How do you prepare a wet mount microscope slide?

Answer 2

-start by pipetting a small drop of water onto the slide, then use tweezers to place your specimen on top of the water drop
-to put the cover slip on, stand the slip upright on the slide, next to the water droplet. Then carefully tilt and lower it so it covers specimen, trying not to get any air bubbles under there as theyll obstruct the view
-once the cover slip is in position, you can add a stain. Put a drop of stain next to one edge of the cover slip. Then put a bit of paper towel next to the opposite edge so the stain gets drawn under the slip across the specimen

Question 3

What are the steps to using a light microscope to view a specimen.

Answer 3

1) start by clipping the slide containing the specimen to the stage
2) select the lowest powered objective lens
3) use the coarse adjustment knob to bring the stage up to just below the objective lens
4) look down the eyepiece, and use the coarse adjustment knob to move the stage up and down until the image is roughly in focus
5) use the fine adjustment knob until you get a clear image of the slide

Question 4

Explain how you use an eyepiece graticule and stage micrometer to measure the size of a specimen

Answer 4

1) line up the eyepiece graticule and the stage micrometer
2) each division on the stage micrometer is 0.1 mm long
3) at this magnification, 1 division on the stage micrometer is the same as 4.5 divisions on the eyepiece graticule
4) to work out the size of 1 division on the eyepiece graticule you need to divide 0.1 by 4.5 (= 0.022mm)
5) so if you look at an object under the microscope at this magnification and it’s 20 eyepiece divisions you know it measures 20 x 0.022 = 0.44mm