Cell Dynamics Flashcards
Why is microscopy important?
~ structure always relates to function
~ cannot see cells w/o one
Magnification
the ratio of an objects image size to its real size
Resolution
a measure of the clarity of the image, ability to see two points as two points
Contrast
the difference in brightness between the light and dark areas of the image
Name the types of light microscopy
Brightfield Fluorescent Confocal Advanced light microscopy Resolution = ~200nm
Brightfield microscopy
light passes directly through specimen, if not stained image has little contrast
~ most cells too thick + colourless
~ staining kills cell = snapshot
Microtome
used to cut sections of a block with specimen inside
Fluorescent microscopy
allows localisation of specific cellular molecules using fluorescent dyes
~ multiple dyes can be used at once
~ cells can be fixed or living
~ immunolabelling
Immunolabelling
when fluorescent dyes are attached to antibodies, used to identify the location + quantity of a specific antigen
Example of fluorescent dye
Rhodamine-labbelled phalloidin
~ fluorochrome-conjugated drug that binds to actin filaments
Confocal microscopy
uses optical sectioning to create an image from a single plane
~ it eliminates out of focus light creating more focus
Advanced light microscopy
~ allows observation of live, unstained transparent cells
Two types:
- phase contrast
- differential interference contrast
Phase contrast
converts differences in phase of the light transmitted through or reflected by the object into differences of intensity in the image
~ uses refracted and un-refracted light
Differential interference contrast
produces contrast by visually displaying the refractive index gradients of different areas of a specimen
~ uses two light beams
Transmission electron microscopy
an image is derived from a broad, static electron beam which has passes through the specimen
~ operates in a vaccum
Resolution = 0.2-0.1nm
