Microscopy Flashcards
Microscopy
Magnification
The ratio of image to the real size
Resolution
The minimum distance that 2 points can be distinguished as 2 points
Contrast
Accentuates (meaning make more noticeable ) differences in parts of the sample
What are the 2 main different types of Microscopy?
Light Microscopy and Electron Microscopy
What is Light Microscopy?
A technique that uses visible light and lenses to magnify the image of small objects
What is Electron Microscopy?
A technique that uses a beam of electrons to produce an enlarged image of a small object.
Scanning Electron Microscopy (SEM)
Topography ( physical features of an area) of a specimen [electrons bounce off gold-coated specimen] which helps produce an image.
Transmission Electron Microscopy (TEM)
Electrons pass through the specimen and are used to look at the internal structures of a cell.
What is Brightfield Microscopy?
One advantage is ..
One disadvantage..
Uses unstained specimen
One advantage- The cell can still be alive
One Downside - The contrast is bad, there’s going to be a problem in defining the different parts of the sample
What is Light Microscopy?
One advantage..
One disadvantage..
Uses stained specimen
One advantage- Uses stain which means you can differentiate the different parts of the cell
One disadvantage is- You’re going to kill the cell due to staining.
What is Phase Contrast?
NOT STAINED (therefore you can use a living cell)
changes the angles of light which helps increase contrast
What is Fluorescence?
A characteristic of a molecule where when it absorbs a photon of light of one wavelength and releases energy in a photon of light in a DIFFERENT wavelength.
What is Fluorescence Microscopy?
Type of Light Microscopy that makes fluorescent substances visible in a microscope.
Only when your in the plane of the sample is it going to be a clear image
How does the size of the sample affect the image in Fluorescence Microscopy?
The thicker the sample the harder it is to get a clear image
The thinner the sample the easier it is to get a clear image.
What is Cell Fractionation?
A process of separating cellular components using centrifugation. ( Separating 2 components)
What is Centrifugation?
A technique used for the separation of particles from a solution according to their size, shape, density, viscosity of the motor speed
What is the mixture and pellet produced by Centrifugation dependent on?
The pellet is dependent on the speed at which we centrifuge our sample.
Heavier molecules/ substances pellet at lower speeds
Smaller molecules/substances pellet at faster speeds
Homogenization
The process when you ‘lyse’ (break) cells which release the components inside the cell
Homogenate
The product of homogenization. It is the uniformed mixture of the cellular components.
What does centrifugation result in?
Results in a pellet and supernate
Supernatant
The substance that didn’t pellet out at the speed, its what stays in the solution.
