Microscopy Flashcards
Which part of the light microscope collects light passing through the specimen and produces a magnified image?
Objective lens
Which lens in a light microscope does not magnify the image?
Condenser lens - this is below the stage and focuses the light onto the specimen.
What is the proper name for the lens at the top of the microscope?
Eyepiece lens
Which light microscope lens will tend to produce the greater magnification?
Objective lens
What is the difference between magnification and resolution?
Magnification describes how much larger the image produced is than the real specimen. e.g. a 1mm specimen magnified 50x appears in the image as 50mm. Resolution describes the sharpness and clarity of the image; how easy it is to distinguish between two separate points within the image. Think about enlarging low quality digital images and the pixelation you see - you have magnified the image but the resolution has decreased.
What are the two forms of radiation used in microscopy?
Light and electrons
What is the study, within Biology, of the preparation of specimens for examination using microscope?
Cytology
Which unit of measurement is 1000x smaller than a mm?
micrometer (µm)
How many micrometers are there in 14mm?
14,000 µm
How many µm in 3.6m?
3,600,000µm
Which unit of measurement is smaller, micrometers or nanometers?
Nanometers (nm)
How many nanometers are in 7mm?
7,000,000nm
How many nanometers are in 46µm?
4,600nm
Why is the letter “µ” used?
“µ” is the greek letter for m, pronounced “mu”. It is used because micrometers starts with an m, but the written shorthand (µm) distinguishes it from millimetres (mm)
What is the maximum resolution of a light microscope?
200nm
How do we calculate the magnification of a microscopy image?
MIA
Magnification = Image size ÷ Actual size
e.g. a 2mm image of a structure that is 5µm wide
2000 ÷ 5 = 400x magnification
(remember to always ensure both numbers are in the same unit - convert if necessary!)
