microscopes Flashcards
(14 cards)
What is magnification?
Size
What is resolution?
how well a microscope distinguishes between 2 points that are close together.
what is the equation for magnification?
magnification = image size/object size
what is 1 micrometer as a millimetre?
1 micrometer = 0.001 millimetre
what are the 3 types of microscopes?
light microscopes, Laser Scanning Confocal Microscopes (special type of light microscope), electron microscope
what is the resolution of a light microscope compared to an electron microscope?
light microscopes have a maximum resolution of 0.2 micrometres and an electron microscope has a much higher resolution.
**so a light microscope has a lower resolution. **
what is the maximum useful magnification of a light microscope?
x1500
how do Laser Scanning Confocal Microscopes work?
They use a laser beam to scan a sepcimen which is usually tagged with a fluorescent dye. the laser causes the dye to fluoresce and that light is then focused through a pinhole onto a detector. the detector is hooked up to a computer which generates a 3D image.
what makes a Laser Scanning Confocal Microscopes image clearer than a normal light microscope?
the pinhole means that any out-of-focus light is blocked, producting a better image.
what do electron microscopes use to form an image?
electrons.
how do TEMs work?
they use electromagnets to focus a beam of electrons which is then transmitted through the specimen.
what are the 2 kinds of electron microscopes?
SEM and TEM (SEM = scanning electron microscope, TEM = transmission electron microscope)
what part of the specimen will absorb more electrons in a TEM?
denser areas
