Types of Microscopes Flashcards
Standard compound microscope
Bright-field
Used to observe stained specimens
Light source is halogen tungsten bulb
Phase microscope
Used to observe unstained slides
Inverted microscope
Phase microscope with a light source and condenser and objectives below the stage
Small working distance
Stereomicroscope
Dissecting microscope
Large working distance
Optics and light source above the specimen
Fluorescent microscope
Most common is epifluorescence
Light is above the specimen, if it comes from below it is transmitted fluorescence
Excitation light passes down through the objective, hits the specimen and then the reflected light from the stain is captured by the objective and is allowed to pass through a barrier filter
Common light source is Mercury HBO 100W bulb
Field diaphragm (Field Stop)
Located at the base
Used to focus light coming from the lamp house
Concentrates light as it is closed
Condenser
Collects light that passes through the field diaphragm and focuses it onto the slide
Condenser or aperture diaphragm
Located within the condenser
Changes the angle of light
When diaphragm is open, maximum resolution, low contrast
When diaphragm is closed, low resolution and high contrast
Achromatic
Objectives that correct for two colors
Blue and red
Apochromatic
Correct for three colors
Blue, green, and red
Factors that affect resolution
Numerical aperture of an objective
Numerical aperture of a condenser
Total magnification
Ocular*objective magnification
Empty magnification
Increasing magnification does not always result in a more detailed image
Results when
Total magnification is > 1000* N.A of the objective
Resolution
Dependent on the matrix size or the number of pixels per inch of screen
AML (M2) karyotype
t(8;21)(q22;q22)
