Microscopy

Question 1

What is the function of a stage micrometre?

Answer 1

To calibrate an eyepiece graticule so it can be used to make measurements.

Question 2

How is an eyepiece graticule calibrated?

Answer 2

Select the desired magnification and objective. Place the stage micrometre on the stage.
Line up the scales of both instruments.
Count the number of divisions on the graticule equivalent to each division on the stage micrometre.
Calculate the length of one division of the eyepiece graticule.

Question 3

Outline the procedure of preparing a slide.

Answer 3

Stain the sample with an appropriate dye. Mount the sample on the slide and place a cover slip carefully on the slide, avoiding air bubbles.

Question 4

What is the formula for magnification?

Answer 4

Image size / actual size

Question 5

What are the requirements for label lines in biological drawings?

Answer 5

Lines must be horizontal, straight and must not cross over other lines

Question 6

Outline the procedure of focusing a light microscope.

Answer 6

Rotate the revolving nosepiece to line up with the lowest power objective lens. Look through the eyepiece and use the coarse adjustment knob to lower the stage to focus the image.
Use the fine adjustment knob to focus the image further.