Microscopes (sem and tem are on paper flashcards)
Transmission electron microscope positives
-uses electrons instead of light
- high magnification (x2 million)
-high resolution
-good detail
Transmission electron microscopes negatives
-2D
-Thin sections must be used
-Specimens must be dead
-Black and white
Scanning electron microscopes positives
-Uses electrons instead of light
-High magnification (x2 million)
-good detail
-3D (can see whole organisms)
Scanning electron microscopes negatives
-Specimens must be dead
-medium resolution
-black and white images
What is differential staining
Stains binding only to specific structures
What stain binds to DNA
Acetic orcein
What stains cellulose and startch
Iodine stains cellulose yellow and starch granules blue/black
How do you prepare specimens
dehydrate and embedding a sample in wax
take sections which are then stained and mounted
How do graticules work
- Put graticule in eyepiece
- Put the stage graticule on the stage with x4 lens
- Align them
- Move up to x10 objective lens
- Align them
How many division in each graticule
100
How many divisions is a stage graticule equivilant to in eyepeice graticule
4 because one stage graticule is the length of 4 divisions on eyepeice
how many stage divisions is 40 eyepiece divisions
100
What is stage graticule used to do
Calibrate (mark with scale) a eyepiece graticule
how many segments in a eyepeice graticule
10
