Practical 1 Flashcards
Why are light microscopes commonly called (compound) light?
Because there are 2 lenses magnifying the specimen; The ocular & objective.
How do you calculate the total mag of a light microscope?
The ocular X objective
Label number 1 and state it’s function
Base- supports the Microscope
Label number 2 and state it’s function
Light source- provides light
Label number 3 and state it’s function
Diaphragm- controls how much light the specimen receives.
Label number 4 and state it’s function
Stage- the place where the slide is placed
Label number 5 and state it’s function
Stage clip- holds the slide in place
Label number 6 &7 and state it’s function
High power objective lens (or low)- further magnify the specimen (requires oil immersion for high power)
Label number 8 and state it’s function
Nose piece- holds the objective lenses
Label number 9 and state it’s function
Arm- supports the upper part of the microscope and is used to carry the microscope.
Label number 10 and state it’s function
Fine focus knob- focuses high power objective lens
Label number 11 and state it’s function
Tube- light travels through
Label number 12 and state it’s function
Coarse focus knob- focuses low objective lens
Label number 13 and state it’s function
Eyepiece lens- magnifies the specimen
At a high power field, the magnification is 100x and diameter is 4mm
whar would the diameter be under a low power field, where magnification is 50x?
8mm
Describe flourescence microscopy
it is a method of microscopy that is based on the fact that some materials are able to give out energy, in the form ofvisible lightwhenirradiated. Sometimes natural substances such as chlorophyll react appropriately, other times adye is needed to give out visible light.
Why do fluorescent materials give out energy in the form of light?
- the photons excite the electrons of the material
- the electron jumps to excited state
- unstable electron moved back and gives out energy in form of light of higher wavelength
What is fluorescent microscopy used for?
detecting structures, molecules, or proteins in a cell.
Give 2 dyes that are used in fluorescence dyes, what color light are needed to activate them, and what color they emit.
- Fluorescein- emits green light when it is excited by blue light
- rhodamine- emits deeps red light when it is excited by green-yellow light
How many fluorescent filter cubes do fluorescence microscopes have and what do they each contain?
There are 3 filter cubes, each containing specific barrier filters and a beam splitting mirror
The filter cubes provide blue, green-yellow, and UV light
