week 2: lab 1 (microscopes) Flashcards
what microscope is used in class?
-light compound microscope
name all 4 objective lens:
-scanning objective 4x
-medium power objective 10x
-high (power) dry objective 40x
-oil immersion objective 100x
what is the function of the “ocular/eyepiece”?
-magnifies the image to be seen by human eyes
-correctly positioned when you see a single circle of light
what is the function of the “body”?
-contains mirrors that bend light into oculars
- causes image to be reversed (right to left) and inverted (top to bottom)
what is the function of the “nosepiece”?
-objectives are attached to the nosepiece therefore rotation of the nosepiece will move the objective lens over to the stage
what is the function of “objectives”?
-contains lenses that magnify the image
-4x, 10x,40x (or 45x), and 100x
what is the function of the “arm”?
-supports nosepiece
-hold on/off toggle & focus adjustment knobs
what are the functions of the “stage/mechanical stage”?
-the stage is the black platform on which slide rest
-mechanical stage (silver apparatus) that holds and moves the slide to position on the stage
what is the function of the “stage adjustment knobs”?
- they move the mechanical stage (silver apparatus) from left to right and top to bottom
what is the function of the “light intensity control”?
- increases/decreases light output
what is the function of the “substage condenser”?
-to focus the light onto the specimen, improves image sharpness
what is the function of the “aperture diaphragm control”?
-controls the amount of light entering substage condenser from the light source
what is the function of the “field diaphragm lever”
-opens and closes to increase/decrease light from the light source
- should remain open
what is the function of the “ light source”?
-illuminator; bulb that produces light
what is the function of the “base”?
-holds the illuminator and supports the rest of the microscope
what is the function of the “fine focus adjustment knob”?
-rotation of the knob brings the image into sharp focus
what is the function of the “coarse focus adjustment knob”?
-this knob moves the stage up and down
what is objective maginification?
-magnification of the objective lens
-example: 4x (scanning) or 100x (oil immersion)
what is total magnification?
-(objective lens magnification) x (ocular lens magnification) = total magnification
-example 4x (scanning) x 10x= 40x total magnification
what is “resolution”?
-shows objects that are close together as separate objects
what is “magnification”?
making an object appear larger with the use of both ocular and objective lens magnification
what is “parfocal lens”?
-parfocal lenses maintain focus when moving from one objective to another
-will only require minor adjustments (fine adjustment)
what is “field of view”?
-what you can see through the ocular lenses
what is “working distance”?
-distance from the objective to the stage
why do we use oil immersion?
-Oil immersion bends light differently
-Allows more light to focus through the specimen (due to its refractive index)
-ONLY USED in 100x objective lens
what are dissecting microscopes used for?
- used to see larger objects, external structures such as a bee
what are electron microscopes used for?
- Creates an image by either passing electrons through the specimen or reflecting electrons off the
specimen - Transmission Electron Microscope
- Scanning Electron Microscope
what are compound light microscopes used for?
- use visible light and a series of lenses to create an image used for seeing living or dead cells too small to be seen with the naked eye
- Bright-Field
- Dark-Field
- Phase-Contrast
what are UV radiation microscopes used for?
- Fluorescence: uses UV radiation to interact with stains, which will fluoresce or glow when activated
- Confocal: uses a laser to pass concentrated UV through thick structures such as tissues
