Flashcards in Lecture 2 Deck (36):
name the 5 types of light microscopes
differential interference contrast
how many occular lenses can a bright field microscope have?
occular lenses come in these 4 sizes
how many objective lenses can a bright field microscope have?
as many as available
objective lenses come in which sizes?
which objective power is used for scanning? which is used for oil immersion?
what is necessary for an organism to be seen under a bright field microscope?
how can you make an organism easier to see under a bright field microscope?
how do you calculate the total magnification?
ocular lens multiplied by the objective lens
what is numerical aperture (NA)?
it tells you how much light bends
how can a clearer image be achieve?
use a lower resultion/increase the numerical aperture
what is the smallest thing visible under a bright field microscope?
.2 micro meter or 200 nano meters
what color light should you use to see the smallest objects?
can you use the bright field microscope to see mycoplasma?
only under the best conditions
can you use the bright field microscope to see viruses?
can you use the bright field microscope to see bacteria?
what modification does the dark field microscope have?
a dark field stop located just under the condensor which blocks the light except for the light around the edges
using a dark field microscope removes the need for __________
can you use live specimens with the bright field microscope?
can you use live specimens for the dark field microscope?
can you use live specimens for the phase contrast microscope?
Name a specific example of an organism which can be seen under a dark field microscope
syphilis treponema pallidum
Can you seen mycoplasma under a dark field microscope?
Name the two modifications on the phase contrast microscope that differ it from the bright field microscope
phase shifting element
what does the annular diaphragm do?
Generates a ring of light which initiates the bending of the light (incident rays). Located below the condenser (lets through a rind of light that helps the light to bend)
what does the phase shifting element do?
controlls the speed of the light by manipulating the brightness
using the phase contrast microscope can you see mycoplasma?
Name the 3 modifications that a fluorescence microscope from a bright field one
exciter filter, barrier filter, fluorescent dye
what does the exciter filter do?
blocks out wavelengths greater than 400nm (lets through UV light only)
what does the barrier filter do?
blocks out wavelengths less than 500nm (protects eyes from UV light and gives a black field)
what does the fluorescent dye do?
absorbs high energy of the light and releases visible light. Stains things with high amounts of lipids
can you see mycobacterium tuberculosis?
what is immunofluorescence?
the fluorescence antibody technique
Uses antibodys and flourescent dye for staining if there is not enough lipid for the dye to stick to the organism
what can you use immunofluorescence to diagnose?
what modification does a differential interference contrast microscope compared to a bright field one?
uses a prism to split the light and then recombine it