3.1 Microscopy Part 3 Flashcards
What are some drawbacks to electron microscopes?
- labor intensive
- require cells to be fixed
- process can alter cellular structure
What does TEM stand for?
transmission electron microscope
How do TEMs function?
use thin slices of s sample that is heavily treated with preservatives and places them between an electron beam and the detector
What can TEMs be used for?
visualize subcellular organelles, substructures, and viral particles
What does SEM stand for?
scanning electron microscope
What is the main difference between SEM and TEMs?
TEM = electron beam goes through the sample
SEM = electron beam reflect off the sample
What are samples coated in for SEMs?
gold or palladium
What is the purpose of the gold and palladium in SEM?
enhance the electron reflection
What can SEM only be used for?
generating a 3D shell model of the surface of a specimen
What are STEHMs?
scanning transmission electron holography microscopes
How does a STEHM function?
uses an electron beam coupled with holography
What is studied with a STEHM?
surfaces of proteins and subcellular structures
How much can a STEHM magnify a sample?
20 million times
