2.1.1 Flashcards
(53 cards)
What is staining?
- Coloured stains bind to chemicals on / in specimen
Why do we use staining?
- allows the specimen to become visible
- can see organelles
- improve contrast
What stains DNA dark red?
Acetic Orcein
What colour does eosin stain the cytoplasm?
pink
Why do we do sectioning?
to allow light to pass through
What is the difference between the uses of the electron microscopes?
TEM - looks at organelle detail
SEM - looks at cell surface
How do SEM’s work?
beam of electrons hits specimen and bounces off
How do TEM’s work?
beam of electrons passes through a specimen
Why can TEM images look different?
organelles have been cut at different planes/angles
What are light microscopes used for?
to look at whole cells and whole tissues
What does magnification mean?
Number of times larger an image is in comparison to the object
What does resolution mean?
ability to distinguish between very small structures that are closer together in detail
What is the magnification of a light microscope?
up to 1500X
What is he maginfication of SEM?
100,000X
What is the magnification of TEM?
up to 500,000
What is the maximum resolving power of a light microscope?
50-200nm
What is the maximum resolving power of SEM?
0.20nm
What is the maximum resolving power of TEM?
0.05 - 1nm
cm to mm?
*10
cm to micrometers?
*10000
cm to nm?
10 , 000, 000
nm to micrometers?
/1000
nm to mm?
/1, 000, 000
nm to cm?
/10, 000, 000