microscopy

Question 1

calibrating eyepiece graticule

Answer 1

• Set magnification.
• Align stage & eyepiece graticules on stage
• Count divisions on the eyepiece graticule per stage micrometer division.
• Use stage micrometer values to calculate 1 eyepiece division.

Question 2

what different stains show

Answer 2

• Acetic orcein → DNA (dark red).
• Eosin → Cytoplasm (pink/red).
• Iodine → Starch (blue-black).
• Methylene blue → DNA (blue).

Question 3

wet mount?

Answer 3

• live specimen
• thin slice
• drop water in center
• add stain to edge
• place cover slip 45 degrees

Question 4

dry mount?

Answer 4

• thin slice
• cover slip ontop

Question 5

using a light microscope

Answer 5

• Clip slide on stage.
• Select lowest-power lens.
• Use coarse adjustment to move stage up/down
• use fine adjustment for focus.

Question 6

measuring with microscope

Answer 6

• actual size = divisions x calibrated value

Question 7

what are good scientific drawing

Answer 7

• No shading.
• straight lines
• magnification included.

Question 8

why use thin specimen?

Answer 8

so light can pass through it