Microscopy and Staining Flashcards
What is magnification?
The capacity of a microscope to enlarge an image uising the lenses in the microscope.
What is resolution?
It allows to distinguish between two adjacent objects and separate them into two objects.
What is resolution limit?
The limit depends on the numerical aperture. It is highly dependent on light and power.
What is contrast?
It allows to differentiate between the cell and surroundings in absorbing or scattering light.
Oragnisms are (blank) so there is a need to create (blank).
tranpsarent, contrast
How is contrast achieved?
Through various stains and dyes
This microscope uses illumination from visible light.
Bright Field Microscope
Light in BFM may come from (blank) or (blank).
external, microscope
How do we see images in BFM?
Light source concentrates light into the condenser, projecting it to the objective lens
How does the condenser work in Dark Field Microscope?
Condenser prevents light from passing through. Light is directed to the sides of the specimen.
What is the Dark Field Microscope used for?
To observe motility
Phase Contrast Microscope relies on?
The refractive indices of cells (ability of cells to alter the speed of light) and the background
True or false. Cells have unique refractive indices, resulting to different brightness.
True
How does Phase Contrast Microscope work?
Amplified by the phase ring in the condenser
What is Phase Contrast Microscope used for?
Used for living organisms that cannot be stained
The Nomarski Microscope is also called?
Differential Interference Contrast [DIC]
This microscope uses a polarizer in the condenser to produce polarized light.
Nomarski
In Nomarski, light passes through a (blank) generating (blank) with different refractive indices.
prism, 2 beams
How does Nomarski work?
Light interfere w/ one another, creating a 3D optical effect, enhancing the subtle differences in cell structures
True or false. Nomarski cannot show internal cell structures and is used to observe motility.
False. Nomarski is used for unstained cells, revealing internal cell structures invisible by BFM without staining.
Fluorescence Microscope uses (blank) that can activate fluorescence molecules in cells.
UV light
Example of naturally occuring activated fluorescence
chlorophylls
Examples of stain that can activate fluorescence?
fluorochromes, DAPI