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What lenses does light pass through in a compound microscope?
condenser lenses, objective lenses, ocular lens
Define total magnification and resolution.
Total magnification - objective lens x ocular lens. The ocular lens is set to 10x. Resolution - the ability to distinguish two objects from eachother
how are brightfield, darkfield, phase-contrast, and fluorescence microscopy similar?
They all need a light source
How are electron microscopy and light microscopy different?
electron microscopes use a beam of electrons instead of a beam of light. Electrons have a shorter wavelength than visible light. Higher resolution than light
Why do electron microscopes have greater resolution than light microscopes?
Electrons have a sgorter wavelength than visible light. Produces a higher resolution image than light microscopes
What does TEM stand for and what is it used for?
Transmission Electron Microscope - Reveals internal structures.
What SEM stand for and what is it used for?
Scanning Electron Microscopy - Scans the surface. Produces 3D images
What is a scanning probe microscope used for?
Scanning-probe can look at actual atoms, used for scanning surfaces at the nanoscale level
Which microscopes would you use to observe unstained cells?
Unstained cells are more productively observed using darkfield, phase-contrast, or DIC microscopy.
Which type of microscopy is most likley used to observe stained cells?
Bright field microscopy
Explain how the phase-contrast microscope works and what we use it for
Brings direct and reflected or diffracted light rays together to form an image of the specimen on the ocular lens. used for detailed observation of living cell
What does DIC stand for and what is it used for?
Differential Interference Contrast, provides a colored, 3D image of living cells.
What is one way fluorescence microscopy is used for?
By labeling specific molecules or organelles with fluorescent markers, researchers can track their movement, localization, and interactions in living cells.
Differentiate an acidic dye from a basic dye.
Basic dyes have a (+) charge; acidic dyes have a (-) charge; Basic dyes attract to (-) charged bacterial cell wall due to their (+) charge
Explain why negative staining involves acidic dyes. Give an example of an acidic dye
uses acidic/anionic dye because its (-)charge is repelled by the (-) charge on the outside of the cell staining the background not the microbe/cell. Nigrosin
What is the purpose of simple staining?
Observe the morphology, shape/arrangement of cells.
