More microscopy - 2.3 (2) Flashcards
Module 2, Chapter 2, 2.3, Page 19 & 20
What is inside of an electron microscope?
a vaccuum to ensure the electron beams travel in straight lines
Samples need to be…
processed in a specific way
Specimen preparation: fixation using…
chemicals or freezing
Specimen preparation: staining with…
heavy metal
Specimen preparation: dehydration with…
solvents
What will samples for a TEM be set in?
resin
Will samples for a TEM possibly be stained again?
yes
What will samples for SEM be fractured to expose?
the inside
What will the samples for a SEM be coated with?
heavy metals
What is inexpensive to buy and operate?
light microscope
What type of microscope is small and portable?
light microscope
Do light microscopes have a simple sample preparation?
yes
What type of microscope does not usually lead to distortion in sample preparation?
light microscope
Is a vacuum required in light microscopy?
no
Can natural colour of samples be seen in light microscopy?
yes
What magnification can light microscopes go up to?
x2000
What resolving power do light microscopes have?
200nm
What kind of specimens can be used in light microscopes?
living or dead
Electron microscopes are expensive to…
buy and operate
Electron microscopes are large and…
need to be installed
What kind of microscope has a complex sample preparation?
electron microscope
Which microscope has a sample preparation that often distorts materials?
electron microscope
Is vacuum required in electron microscopes?
yes
What colour images are produced in electron microscopes?
black and white (but can be coloured digitally)
What magnification can electron microscopes have up to?
x500 000
What resolving power do transmission electron microscopes have?
0.5nm
What resolving power do scanning electron microscopes have?
3-10nm
Specimens are…
dead in electron microscopes
