microscopy Flashcards
name the two lenses in a compound light microscope
the objective lens, which is placed near to the specimen and the eyepiece lens, through which the specimen is viewed.
Define magnification
magnification is how many times larger the image is than the actual size of the object being viewed.
Define resolution
Resolution is the ability for a microscope to distinguish between two points that are close together.
How do you calculate magnification?
Magnification= Image size/ Actual size of the object.
What is a dry mount?
A dry mount is where the thing you plan to observe is placed on the slide with a cover slip over it. No water is needed. This kind of mount is usually used for inanimate objects or things that do not need water to live.
How do you prepare a dry mount slide?
solid specimens are viewed whole or cut into very thin slices with a sharp blade (sectioning). The specimen is placed on the center of of the slide and a cover slip is placed over the sample.
How do you prepare a wet mount slide?
specimens are suspended in liquid such as water or an immersion oil. A cover slip is placed on from an angle.
How do you prepare a squash slide?
A wet mount is first prepared, then a lens tissue is used to gently press down on the cover slip. Care needs to be taken to make sure the cover slip is not broken when it’s being pressed.
How do you prepare a smear slide?
The edge of the slide is used to smear the sample creating a thin even coating on another slide. A cover slip is then placed over the sample.
How do Transmission Electron Microscopes work?
A beam of electrons is transmitted through a specimen and focused to produce an image.
what is the resolving power of a TEM microscope?
0.5nm
What is a SEM microscope?
In a scanning electron microscope (SEM) a beam of electrons is sent across the of a specimen and the reflected electrons are collected.
What is the resolving power of a SEM microscope?
3-10nm
What is special about a SEM microscope?
It produces 3D images that scientists can study in more detail.
