Lab Knowledge Flashcards
What is chromatography used for?
Chromatography uses samples from 2 organisms to find genetic/ancestral similarities and separates substances based on solubility.
What does a centrifuge do?
A centrifuge separates liquids based on density.
What is gel electrophoresis used for?
Gel electrophoresis is used to separate DNA substances according to size.
How does DNA move through the gel in gel electrophoresis?
DNA moves through the gel because it is negatively charged and moves towards the positive end when an electric current is applied.
Where are DNA samples loaded in gel electrophoresis?
DNA samples are loaded at the negative end of the gel, which attracts the DNA towards the positive end.
How are DNA fragments sorted in gel electrophoresis?
DNA is sorted by size: smaller fragments move faster and travel farther through the gel to the positive side.
How are wells created in gel electrophoresis?
Wells are created by placing a comb in the gel before it solidifies.
What is the purpose of loading dye in gel electrophoresis?
Loading dye is mixed with DNA samples to help visualize DNA as it moves through the gel.
What does the buffer do in gel electrophoresis?
The buffer maintains a stable pH during electrophoresis and allows DNA to move efficiently through the gel.
What is the ocular magnification of a microscope?
The ocular magnification is approximately 10X.
What are the objective magnifications of a microscope?
Objective magnifications include: Scanning Power ~ 4X, Low Power ~ 10X, High Power ~ 40X.
How do you calculate total magnification in a microscope?
Total magnification = Ocular (10X) x objective.
What is resolving power in microscopy?
Resolving power is the ability to distinguish between two objects; high resolution means more detail.
What is a compound light microscope?
A compound light microscope is the most common classroom microscope where the image is inverted and reversed.
What does a scanning electron microscope do?
A scanning electron microscope runs a beam of electrons back and forth across the surface to make a 3D image (topography).
What is the total magnification range of a scanning electron microscope?
The total magnification range of a scanning electron microscope is 30x-30,000x.
What does a transmission electron microscope do?
A transmission electron microscope shines a beam of electrons through a thin slice of specimen (0.1 µm) to create a cross section and makes a 2D image.
What is the total magnification of a transmission electron microscope?
The total magnification of a transmission electron microscope is 500,000x.
