microscopy Flashcards
how to increase magnification
decrease the focal length
what does convex lens do
converges parallel beams to the focal point
what does focal length depend on
curvature of lens
more curved- shorter focal length
what is fluorescence microscopy
different parts of the cells are stained using specific dyes or antibodies
specimen is illuminated with light of particular wavelength which excites the flurophore
light of longer wavelength is emitted
what is immunofluorescence
primary antibody binds to antigen on specimen
secondary antibody with a fluorescent tag binds to primary antibody
what is GFP
green fluorescent protein is used as a tag and allows protein behaviour to be visualised in live cells
what is confocal microscopy
improves clarity and resolution , pinhole prevents out of focus light reaching the detector
how many x greater resolution is electron microscopy than light microscopy
2000x
2 types of electron microscopy and their results
TEM- 2D image of thin specimen
SEM-3D image of specimen of unlimited thickness
what happens during SEM
primary beam of electrons focused on a fine point
these are scanned across the surface and secondary electrons emitted
secondary electrons are detected to build a picture
which lens focuses and magnifies the image
objective lens
