Lecture 4 Flashcards
Magnification
Enlarging an object visually, not physically
Resolution
How much detail can be seen, how close two objects can be and still be separated clearly in the image
Contrast
How distinct the specimen is from the background, can be enhanced by staining or optical tricks
Immersion Oil
The image isn’t distorted in oil. It is improved. It increases the resolution
Bright Field Microscope
Has 3 lens. Focuses the light to a point on an object.
Dark Field Microscope
Uses a special condenser; metal plate goes over the light source to scatter the light beam; the back group is dark and the objects in view light up
Dark Field Condenser
Shines the light in a circle on the outer rim. Not directly on the object
Phase Contrast Microscope
Uses phase-shifting of refracted light caused by photon drag to enhance contrast
Phase Plate
Phase shifting element on the phase contrast microscope
Differential Interference Contrast Microscope
Also called Interference Microscope. It uses 2 beams of 90degree polarized light to detect 3D details in the sample
Wollaston Prism
It separates polarized light and redirects it
90degree Polarized Light
The Differential Interference Contrast Microscope uses 2 beams of this light to detect 3D details
Fluorescence Microscope
Uses the dye flurophore. Uses excitation wavelength as illuminating light. The partials glow fluorescently.
Confocal Scanning Laser Microscope
Uses an aperture to shut out light from all but one focal plane of the object. You look at a 3D colorful multi layer image of the object
Confocal Pinhole
A smaller pinhole allows a small amount of light is better for viewing the image
Transmission Electron Microscope
TEM. Electron beam passes through the specimen just like a beam of light. The beam is an x-ray. And instead of lenses it uses magnets
Scanning Electron Microscope
SEM. Detects electrons and x-rays scattered from a surface. Dramatic 3D views at variable magnification. It is a weaker beam and needs a much more sensitive detector.
Electron Cryotomography
At cold temperatures and views multiple angles at the same time. Its a CAT scan for microbes. Its views parts inside of a specimen. Needs a really weak beam
Atomic Force Microscope
4D microscopy. Electron field is monitored at the tip of a nanotube probe. Field varies as probe is pushed over a surface. Can see atoms
Simple Stain
Basic (+) dye attaches to (-) phospholipid head groups
Differential Stain
More than one stain is used. pink=thin(Gram -)
Purple=thick(Gram +)
Acid-Fast Stain
Differentiates based on waxy coating impervious to acidified alcohol. Red= acid-fast, blue=not
Negative Stain
Stains the background not the cell. To show the uncharged electrons. Uses partials to stain the background instead of dyes
