Lecture 3 Microscopy Flashcards
what is light vs electron microscopy
Light- shining photons
Electron- electrons on specimen
cells are relatively easy to see because they are _____
thin
what is a microtome
a machine that makes thin slices
Light Microscopy: light source
halogen
Light Microscopy: condenser
focuses light on the specimen
Light Microscopy: specimen
light goes through the specimen
Light Microscopy: objective
focuses and magnifies light from the specimen
Light Microscopy: ocular
lens that you look through
How do you make a bright field better
stain, phase contrast, DIC (differential interference microscopy)
what is phase contrast
uses diffraction rings in the condenser and objective
what is DIC
it polarizes light before and after the specimen
what is fluorophore
absorbs one wavelength of light and emits another
Fluorescence Microscopy: Light source
mercury lamp
Fluorescence Microscopy: excitation filter
allows only a specific wavelength go through
Fluorescence Microscopy: dischroic
reflects excitation light onto the specimen
Fluorescence Microscopy: sample
flurorophore absorbs excitation light and reflects back emission light
Fluorescence Microscopy: epifluorescence
looking at light from the same side as the excitation light
Fluorescence Microscopy: dichroic (2nd time)
allow emission light from the same side as the excitation light
Fluorescence Microscopy: emission folter
allows only emission wavelengths through
what is immunofluorescence
uses a fluorescent antibody to localize a specific wavelength
what is GFP-tagging
green fluorescent protein which is attached to a particular protein to show where it localizes
what is FRET
used to study if two proteins are next to each other
what is FISH
used to show where specific DNA sequences are in a chromosome
what is FRAP
used to study rate of lateral movement
what is immunogold
it uses antibodies attached to gold particles
what is tomography
taking images of several layers and then constructing a 3D image (CAT scan)
what is a negative stain EM
it involves submerging the sample in electron dense liquid