WEEK 1-3 MATERIAL BIOL4004 EXAM QUESTIONS AND
ANSWERS WITH COMPLETE SOLUTIONS GRADED A++
What is the difference of light and electron microscopy?
interaction of light with tissue vs. interaction of electrons with tissue
What does electron microscopy allow you to see more clearly?
macromolecules and subcellular structures
Define detection
the ability to determine the presence of an object
Define resolution
The ability to distinguish between two objects close together
Define the limit of resolution
The smallest distance in which you can distinguish between two objects
Define numerical aperature
Light gathering ability of lens
Equation of limit of resolution
0.61*wavelength/numerical aperature
Relationship of numerical aperature and resolution
as NA increases, so does resolution
Define magnification
the ratio of an object's image size to its real size
Relationship of resolution and magnification
,As magnification increases, its easier to resolve
Define empty magnification
Magnification at or beyond which there is no increase in detail
Lenses of compound light microscope
condenser, objective, tube, ocular
What are the 3 methods to see clear, colorless cells
stain, light scatter, light wave phase
What are the 4 types of light microscopy
brightfield, phase contrast, nomarski differential interference contrast, dark field
How to prepare tissues for microscopy?
1. fixation - uses chemicals to preserve cell and tissue structure and crosslink proteins
2. embedding - place tissue in supporting medium
3. sectioning - slice tissue thin enough for light to pass through
4. stain - add contrast to view in microscopy
What tool is used to section tissue?
Microtome
How does brightfield microscopy work?
Stains with specific colors used to bind specific cellular components
What does histo mean?
Tissue
, What is immunocytochemistry?
Using antibodies to strain specific structures or proteins
What is direct immunocytochemistry?
A detectable marker is attached to an antibody that binds a specific antigen/protein
What is indirect immunocytochemistry?
A primary antibody binds to a protein/antigen, a secondary antibody is bound to a
marker
How is indirect immunocytochemistry flexible?
Secondary antibodies can recognize the constant region of primary antibodies (which is
identical in each isotope)
How does enzyme immunohistochemistry work?
For detecting proteins. Secondary antibodies attached to enzyme. With an added
substrate, the enzyme makes a colored product.
What is fluorescence microscopy?
uses specific fluorescent molecules to stain certain molecules or structures
How do fluorescent molecules work?
They absorb light at a wavelength and emit a higher wavelength
What is immunofluorescence?
Immunocytochemistry with secondary antibodies attached to a fluorophore
What type of microscopy is best for looking at live cells?
DIC or Normarski
What type of microscopy is best for looking at a specific type of cells within a
tissue? What technique is used see location?
ANSWERS WITH COMPLETE SOLUTIONS GRADED A++
What is the difference of light and electron microscopy?
interaction of light with tissue vs. interaction of electrons with tissue
What does electron microscopy allow you to see more clearly?
macromolecules and subcellular structures
Define detection
the ability to determine the presence of an object
Define resolution
The ability to distinguish between two objects close together
Define the limit of resolution
The smallest distance in which you can distinguish between two objects
Define numerical aperature
Light gathering ability of lens
Equation of limit of resolution
0.61*wavelength/numerical aperature
Relationship of numerical aperature and resolution
as NA increases, so does resolution
Define magnification
the ratio of an object's image size to its real size
Relationship of resolution and magnification
,As magnification increases, its easier to resolve
Define empty magnification
Magnification at or beyond which there is no increase in detail
Lenses of compound light microscope
condenser, objective, tube, ocular
What are the 3 methods to see clear, colorless cells
stain, light scatter, light wave phase
What are the 4 types of light microscopy
brightfield, phase contrast, nomarski differential interference contrast, dark field
How to prepare tissues for microscopy?
1. fixation - uses chemicals to preserve cell and tissue structure and crosslink proteins
2. embedding - place tissue in supporting medium
3. sectioning - slice tissue thin enough for light to pass through
4. stain - add contrast to view in microscopy
What tool is used to section tissue?
Microtome
How does brightfield microscopy work?
Stains with specific colors used to bind specific cellular components
What does histo mean?
Tissue
, What is immunocytochemistry?
Using antibodies to strain specific structures or proteins
What is direct immunocytochemistry?
A detectable marker is attached to an antibody that binds a specific antigen/protein
What is indirect immunocytochemistry?
A primary antibody binds to a protein/antigen, a secondary antibody is bound to a
marker
How is indirect immunocytochemistry flexible?
Secondary antibodies can recognize the constant region of primary antibodies (which is
identical in each isotope)
How does enzyme immunohistochemistry work?
For detecting proteins. Secondary antibodies attached to enzyme. With an added
substrate, the enzyme makes a colored product.
What is fluorescence microscopy?
uses specific fluorescent molecules to stain certain molecules or structures
How do fluorescent molecules work?
They absorb light at a wavelength and emit a higher wavelength
What is immunofluorescence?
Immunocytochemistry with secondary antibodies attached to a fluorophore
What type of microscopy is best for looking at live cells?
DIC or Normarski
What type of microscopy is best for looking at a specific type of cells within a
tissue? What technique is used see location?
