Microscopy Basic Concepts Flashcards
Why did Leewenhoek make so many Microscopes?
Because they were very hard to focus. Once he has a specimen in focus he would craft a new scope to view the next.
What is the limit of the naked eye?
we are unable to see objects that are less than 0.1mm
Define Microbiology.
The study of microorganisms
What is the approximate size of the smallest bacteria?
0.5 micrometer
1 micrometer = 1/1000 mm
can viruses be observes with a compound light microscope?
No. They can be vied with an transmission electron microscope.
They are measured in nano-meters
1 nm = 1/1000 micrometer
What are the three concepts of microscopy?
Magnification, resolving power, contrast.
Define magnification.
The factor by which the image is enlarged
Define resolving power.
the degree to which two adjacent points in a specimen are seen as separate.
Define Contrast.
Determines how well the image stands out against the background.
Why is magnification important.
The whole point of Microscopy is to make images larger so without magnification microscopy would not exist.
Why is resolving power important.
it determines the sharpness of the image. It doesn’t matter how enlarged the image is if it is blurry.
Why is contrast important.
Without contrast you cant see the image.
What is the eyepiece/ocular lens?
the lens through which the object is viewed.
What is the objective lens?
magnifies and projects the image.
How many objective lenses are there on the standard compound light microscope? name them
4 LPO-low power objective MPO-medium power objective HPO-high power objective OIO- Oil immersion objective
what is the revolving nose piece?
Where the objective lenses are mounted
What is the stage?
the platform where you put the slide
What are the stage clips?
they fasten the slide to the stage
What is the mechanical stage knob?
moves the stage to locate the specimen
What is the condenser?
concentrates the light going to the specimen
What is the iris diaphragm lever?
opens and closes the condenser
What is the course adjustment knob?
for bringing the object into approximate focus
What is the fine adjustment knob?
for final focusing. Only one you use with OIO
what is the light source?
Located at the base of the microscope. provides direct illumination
what is the light intensity dial?
adjusts the light intensity from 1 to 10
what is the arm?
used for proper handling of the microscope
What objective do you always focus with first
The LPO
What does it mean to be par focal?
When one objective is focused the others are automatically in course focus
